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*/
/** * An interpreter for printf-style format strings. This class provides support * for layout justification and alignment, common formats for numeric, string, * and date/time data, and locale-specific output. Common Java types such as * {@code byte}, {@link java.math.BigDecimal BigDecimal}, and {@link Calendar} * are supported. Limited formatting customization for arbitrary user types is * provided through the {@link Formattable} interface. * * <p> Formatters are not necessarily safe for multithreaded access. Thread * safety is optional and is the responsibility of users of methods in this * class. * * <p> Formatted printing for the Java language is heavily inspired by C's * {@code printf}. Although the format strings are similar to C, some * customizations have been made to accommodate the Java language and exploit * some of its features. Also, Java formatting is more strict than C's; for * example, if a conversion is incompatible with a flag, an exception will be * thrown. In C inapplicable flags are silently ignored. The format strings * are thus intended to be recognizable to C programmers but not necessarily * completely compatible with those in C. * * <p> Examples of expected usage: * * <blockquote><pre> * StringBuilder sb = new StringBuilder(); * // Send all output to the Appendable object sb * Formatter formatter = new Formatter(sb, Locale.US); * * // Explicit argument indices may be used to re-order output. * formatter.format("%4$2s %3$2s %2$2s %1$2s", "a", "b", "c", "d") * // -> " d c b a" * * // Optional locale as the first argument can be used to get * // locale-specific formatting of numbers. The precision and width can be * // given to round and align the value. * formatter.format(Locale.FRANCE, "e = %+10.4f", Math.E); * // -> "e = +2,7183" * * // The '(' numeric flag may be used to format negative numbers with * // parentheses rather than a minus sign. Group separators are * // automatically inserted. * formatter.format("Amount gained or lost since last statement: $ %(,.2f", * balanceDelta); * // -> "Amount gained or lost since last statement: $ (6,217.58)" * </pre></blockquote> * * <p> Convenience methods for common formatting requests exist as illustrated * by the following invocations: * * <blockquote><pre> * // Writes a formatted string to System.out. * System.out.format("Local time: %tT", Calendar.getInstance()); * // -> "Local time: 13:34:18" * * // Writes formatted output to System.err. * System.err.printf("Unable to open file '%1$s': %2$s", * fileName, exception.getMessage()); * // -> "Unable to open file 'food': No such file or directory" * </pre></blockquote> * * <p> Like C's {@code sprintf(3)}, Strings may be formatted using the static * method {@link String#format(String,Object...) String.format}: * * <blockquote><pre> * // Format a string containing a date. * import java.util.Calendar; * import java.util.GregorianCalendar; * import static java.util.Calendar.*; * * Calendar c = new GregorianCalendar(1995, MAY, 23); * String s = String.format("Duke's Birthday: %1$tb %1$te, %1$tY", c); * // -> s == "Duke's Birthday: May 23, 1995" * </pre></blockquote> * * <h2><a id="org">Organization</a></h2> * * <p> This specification is divided into two sections. The first section, <a * href="#summary">Summary</a>, covers the basic formatting concepts. This * section is intended for users who want to get started quickly and are * familiar with formatted printing in other programming languages. The second * section, <a href="#detail">Details</a>, covers the specific implementation * details. It is intended for users who want more precise specification of * formatting behavior. * * <h2><a id="summary">Summary</a></h2> * * <p> This section is intended to provide a brief overview of formatting * concepts. For precise behavioral details, refer to the <a * href="#detail">Details</a> section. * * <h3><a id="syntax">Format String Syntax</a></h3> * * <p> Every method which produces formatted output requires a <i>format * string</i> and an <i>argument list</i>. The format string is a {@link * String} which may contain fixed text and one or more embedded <i>format * specifiers</i>. Consider the following example: * * <blockquote><pre> * Calendar c = ...; * String s = String.format("Duke's Birthday: %1$tm %1$te,%1$tY", c); * </pre></blockquote> * * This format string is the first argument to the {@code format} method. It * contains three format specifiers "{@code %1$tm}", "{@code %1$te}", and * "{@code %1$tY}" which indicate how the arguments should be processed and * where they should be inserted in the text. The remaining portions of the * format string are fixed text including {@code "Dukes Birthday: "} and any * other spaces or punctuation. * * The argument list consists of all arguments passed to the method after the * format string. In the above example, the argument list is of size one and * consists of the {@link java.util.Calendar Calendar} object {@code c}. * * <ul> * * <li> The format specifiers for general, character, and numeric types have * the following syntax: * * <blockquote><pre> * %[argument_index$][flags][width][.precision]conversion * </pre></blockquote> * * <p> The optional <i>argument_index</i> is a decimal integer indicating the * position of the argument in the argument list. The first argument is * referenced by "{@code 1$}", the second by "{@code 2$}", etc. * * <p> The optional <i>flags</i> is a set of characters that modify the output * format. The set of valid flags depends on the conversion. * * <p> The optional <i>width</i> is a positive decimal integer indicating * the minimum number of characters to be written to the output. * * <p> The optional <i>precision</i> is a non-negative decimal integer usually * used to restrict the number of characters. The specific behavior depends on * the conversion. * * <p> The required <i>conversion</i> is a character indicating how the * argument should be formatted. The set of valid conversions for a given * argument depends on the argument's data type. * * <li> The format specifiers for types which are used to represents dates and * times have the following syntax: * * <blockquote><pre> * %[argument_index$][flags][width]conversion * </pre></blockquote> * * <p> The optional <i>argument_index</i>, <i>flags</i> and <i>width</i> are * defined as above. * * <p> The required <i>conversion</i> is a two character sequence. The first * character is {@code 't'} or {@code 'T'}. The second character indicates * the format to be used. These characters are similar to but not completely * identical to those defined by GNU {@code date} and POSIX * {@code strftime(3c)}. * * <li> The format specifiers which do not correspond to arguments have the * following syntax: * * <blockquote><pre> * %[flags][width]conversion * </pre></blockquote> * * <p> The optional <i>flags</i> and <i>width</i> is defined as above. * * <p> The required <i>conversion</i> is a character indicating content to be * inserted in the output. * * </ul> * * <h3> Conversions </h3> * * <p> Conversions are divided into the following categories: * * <ol> * * <li> <b>General</b> - may be applied to any argument * type * * <li> <b>Character</b> - may be applied to basic types which represent * Unicode characters: {@code char}, {@link Character}, {@code byte}, {@link * Byte}, {@code short}, and {@link Short}. This conversion may also be * applied to the types {@code int} and {@link Integer} when {@link * Character#isValidCodePoint} returns {@code true} * * <li> <b>Numeric</b> * * <ol> * * <li> <b>Integral</b> - may be applied to Java integral types: {@code byte}, * {@link Byte}, {@code short}, {@link Short}, {@code int} and {@link * Integer}, {@code long}, {@link Long}, and {@link java.math.BigInteger * BigInteger} (but not {@code char} or {@link Character}) * * <li><b>Floating Point</b> - may be applied to Java floating-point types: * {@code float}, {@link Float}, {@code double}, {@link Double}, and {@link * java.math.BigDecimal BigDecimal} * * </ol> * * <li> <b>Date/Time</b> - may be applied to Java types which are capable of * encoding a date or time: {@code long}, {@link Long}, {@link Calendar}, * {@link Date} and {@link TemporalAccessor TemporalAccessor} * * <li> <b>Percent</b> - produces a literal {@code '%'} * (<code>'\u0025'</code>) * * <li> <b>Line Separator</b> - produces the platform-specific line separator * * </ol> * * <p> For category <i>General</i>, <i>Character</i>, <i>Numeric</i>, * <i>Integral</i> and <i>Date/Time</i> conversion, unless otherwise specified, * if the argument <i>arg</i> is {@code null}, then the result is "{@code null}". * * <p> The following table summarizes the supported conversions. Conversions * denoted by an upper-case character (i.e. {@code 'B'}, {@code 'H'}, * {@code 'S'}, {@code 'C'}, {@code 'X'}, {@code 'E'}, {@code 'G'}, * {@code 'A'}, and {@code 'T'}) are the same as those for the corresponding * lower-case conversion characters except that the result is converted to * upper case according to the rules of the prevailing {@link java.util.Locale * Locale}. If there is no explicit locale specified, either at the * construction of the instance or as a parameter to its method * invocation, then the {@link java.util.Locale.Category#FORMAT default locale} * is used. * * * <table class="striped"> * <caption style="display:none">genConv</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Argument Category * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * <tr><th scope="row" style="vertical-align:top"> {@code 'b'}, {@code 'B'} * <td style="vertical-align:top"> general * <td> If the argument <i>arg</i> is {@code null}, then the result is * "{@code false}". If <i>arg</i> is a {@code boolean} or {@link * Boolean}, then the result is the string returned by {@link * String#valueOf(boolean) String.valueOf(arg)}. Otherwise, the result is * "true". * * <tr><th scope="row" style="vertical-align:top"> {@code 'h'}, {@code 'H'} * <td style="vertical-align:top"> general * <td> The result is obtained by invoking * {@code Integer.toHexString(arg.hashCode())}. * * <tr><th scope="row" style="vertical-align:top"> {@code 's'}, {@code 'S'} * <td style="vertical-align:top"> general * <td> If <i>arg</i> implements {@link Formattable}, then * {@link Formattable#formatTo arg.formatTo} is invoked. Otherwise, the * result is obtained by invoking {@code arg.toString()}. * * <tr><th scope="row" style="vertical-align:top">{@code 'c'}, {@code 'C'} * <td style="vertical-align:top"> character * <td> The result is a Unicode character * * <tr><th scope="row" style="vertical-align:top">{@code 'd'} * <td style="vertical-align:top"> integral * <td> The result is formatted as a decimal integer * * <tr><th scope="row" style="vertical-align:top">{@code 'o'} * <td style="vertical-align:top"> integral * <td> The result is formatted as an octal integer * * <tr><th scope="row" style="vertical-align:top">{@code 'x'}, {@code 'X'} * <td style="vertical-align:top"> integral * <td> The result is formatted as a hexadecimal integer * * <tr><th scope="row" style="vertical-align:top">{@code 'e'}, {@code 'E'} * <td style="vertical-align:top"> floating point * <td> The result is formatted as a decimal number in computerized * scientific notation * * <tr><th scope="row" style="vertical-align:top">{@code 'f'} * <td style="vertical-align:top"> floating point * <td> The result is formatted as a decimal number * * <tr><th scope="row" style="vertical-align:top">{@code 'g'}, {@code 'G'} * <td style="vertical-align:top"> floating point * <td> The result is formatted using computerized scientific notation or * decimal format, depending on the precision and the value after rounding. * * <tr><th scope="row" style="vertical-align:top">{@code 'a'}, {@code 'A'} * <td style="vertical-align:top"> floating point * <td> The result is formatted as a hexadecimal floating-point number with * a significand and an exponent. This conversion is <b>not</b> supported * for the {@code BigDecimal} type despite the latter's being in the * <i>floating point</i> argument category. * * <tr><th scope="row" style="vertical-align:top">{@code 't'}, {@code 'T'} * <td style="vertical-align:top"> date/time * <td> Prefix for date and time conversion characters. See <a * href="#dt">Date/Time Conversions</a>. * * <tr><th scope="row" style="vertical-align:top">{@code '%'} * <td style="vertical-align:top"> percent * <td> The result is a literal {@code '%'} (<code>'\u0025'</code>) * * <tr><th scope="row" style="vertical-align:top">{@code 'n'} * <td style="vertical-align:top"> line separator * <td> The result is the platform-specific line separator * * </tbody> * </table> * * <p> Any characters not explicitly defined as conversions are illegal and are * reserved for future extensions. * * <h3><a id="dt">Date/Time Conversions</a></h3> * * <p> The following date and time conversion suffix characters are defined for * the {@code 't'} and {@code 'T'} conversions. The types are similar to but * not completely identical to those defined by GNU {@code date} and POSIX * {@code strftime(3c)}. Additional conversion types are provided to access * Java-specific functionality (e.g. {@code 'L'} for milliseconds within the * second). * * <p> The following conversion characters are used for formatting times: * * <table class="striped"> * <caption style="display:none">time</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * <tr><th scope="row" style="vertical-align:top"> {@code 'H'} * <td> Hour of the day for the 24-hour clock, formatted as two digits with * a leading zero as necessary i.e. {@code 00 - 23}. * * <tr><th scope="row" style="vertical-align:top">{@code 'I'} * <td> Hour for the 12-hour clock, formatted as two digits with a leading * zero as necessary, i.e. {@code 01 - 12}. * * <tr><th scope="row" style="vertical-align:top">{@code 'k'} * <td> Hour of the day for the 24-hour clock, i.e. {@code 0 - 23}. * * <tr><th scope="row" style="vertical-align:top">{@code 'l'} * <td> Hour for the 12-hour clock, i.e. {@code 1 - 12}. * * <tr><th scope="row" style="vertical-align:top">{@code 'M'} * <td> Minute within the hour formatted as two digits with a leading zero * as necessary, i.e. {@code 00 - 59}. * * <tr><th scope="row" style="vertical-align:top">{@code 'S'} * <td> Seconds within the minute, formatted as two digits with a leading * zero as necessary, i.e. {@code 00 - 60} ("{@code 60}" is a special * value required to support leap seconds). * * <tr><th scope="row" style="vertical-align:top">{@code 'L'} * <td> Millisecond within the second formatted as three digits with * leading zeros as necessary, i.e. {@code 000 - 999}. * * <tr><th scope="row" style="vertical-align:top">{@code 'N'} * <td> Nanosecond within the second, formatted as nine digits with leading * zeros as necessary, i.e. {@code 000000000 - 999999999}. * * <tr><th scope="row" style="vertical-align:top">{@code 'p'} * <td> Locale-specific {@linkplain * java.text.DateFormatSymbols#getAmPmStrings morning or afternoon} marker * in lower case, e.g."{@code am}" or "{@code pm}". Use of the conversion * prefix {@code 'T'} forces this output to upper case. * * <tr><th scope="row" style="vertical-align:top">{@code 'z'} * <td> <a href="http://www.ietf.org/rfc/rfc0822.txt">RFC 822</a> * style numeric time zone offset from GMT, e.g. {@code -0800}. This * value will be adjusted as necessary for Daylight Saving Time. For * {@code long}, {@link Long}, and {@link Date} the time zone used is * the {@linkplain TimeZone#getDefault() default time zone} for this * instance of the Java virtual machine. * * <tr><th scope="row" style="vertical-align:top">{@code 'Z'} * <td> A string representing the abbreviation for the time zone. This * value will be adjusted as necessary for Daylight Saving Time. For * {@code long}, {@link Long}, and {@link Date} the time zone used is * the {@linkplain TimeZone#getDefault() default time zone} for this * instance of the Java virtual machine. The Formatter's locale will * supersede the locale of the argument (if any). * * <tr><th scope="row" style="vertical-align:top">{@code 's'} * <td> Seconds since the beginning of the epoch starting at 1 January 1970 * {@code 00:00:00} UTC, i.e. {@code Long.MIN_VALUE/1000} to * {@code Long.MAX_VALUE/1000}. * * <tr><th scope="row" style="vertical-align:top">{@code 'Q'} * <td> Milliseconds since the beginning of the epoch starting at 1 January * 1970 {@code 00:00:00} UTC, i.e. {@code Long.MIN_VALUE} to * {@code Long.MAX_VALUE}. * * </tbody> * </table> * * <p> The following conversion characters are used for formatting dates: * * <table class="striped"> * <caption style="display:none">date</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top">{@code 'B'} * <td> Locale-specific {@linkplain java.text.DateFormatSymbols#getMonths * full month name}, e.g. {@code "January"}, {@code "February"}. * * <tr><th scope="row" style="vertical-align:top">{@code 'b'} * <td> Locale-specific {@linkplain * java.text.DateFormatSymbols#getShortMonths abbreviated month name}, * e.g. {@code "Jan"}, {@code "Feb"}. * * <tr><th scope="row" style="vertical-align:top">{@code 'h'} * <td> Same as {@code 'b'}. * * <tr><th scope="row" style="vertical-align:top">{@code 'A'} * <td> Locale-specific full name of the {@linkplain * java.text.DateFormatSymbols#getWeekdays day of the week}, * e.g. {@code "Sunday"}, {@code "Monday"} * * <tr><th scope="row" style="vertical-align:top">{@code 'a'} * <td> Locale-specific short name of the {@linkplain * java.text.DateFormatSymbols#getShortWeekdays day of the week}, * e.g. {@code "Sun"}, {@code "Mon"} * * <tr><th scope="row" style="vertical-align:top">{@code 'C'} * <td> Four-digit year divided by {@code 100}, formatted as two digits * with leading zero as necessary, i.e. {@code 00 - 99} * * <tr><th scope="row" style="vertical-align:top">{@code 'Y'} * <td> Year, formatted as at least four digits with leading zeros as * necessary, e.g. {@code 0092} equals {@code 92} CE for the Gregorian * calendar. * * <tr><th scope="row" style="vertical-align:top">{@code 'y'} * <td> Last two digits of the year, formatted with leading zeros as * necessary, i.e. {@code 00 - 99}. * * <tr><th scope="row" style="vertical-align:top">{@code 'j'} * <td> Day of year, formatted as three digits with leading zeros as * necessary, e.g. {@code 001 - 366} for the Gregorian calendar. * * <tr><th scope="row" style="vertical-align:top">{@code 'm'} * <td> Month, formatted as two digits with leading zeros as necessary, * i.e. {@code 01 - 13}. * * <tr><th scope="row" style="vertical-align:top">{@code 'd'} * <td> Day of month, formatted as two digits with leading zeros as * necessary, i.e. {@code 01 - 31} * * <tr><th scope="row" style="vertical-align:top">{@code 'e'} * <td> Day of month, formatted as two digits, i.e. {@code 1 - 31}. * * </tbody> * </table> * * <p> The following conversion characters are used for formatting common * date/time compositions. * * <table class="striped"> * <caption style="display:none">composites</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top">{@code 'R'} * <td> Time formatted for the 24-hour clock as {@code "%tH:%tM"} * * <tr><th scope="row" style="vertical-align:top">{@code 'T'} * <td> Time formatted for the 24-hour clock as {@code "%tH:%tM:%tS"}. * * <tr><th scope="row" style="vertical-align:top">{@code 'r'} * <td> Time formatted for the 12-hour clock as {@code "%tI:%tM:%tS %Tp"}. * The location of the morning or afternoon marker ({@code '%Tp'}) may be * locale-dependent. * * <tr><th scope="row" style="vertical-align:top">{@code 'D'} * <td> Date formatted as {@code "%tm/%td/%ty"}. * * <tr><th scope="row" style="vertical-align:top">{@code 'F'} * <td> <a href="http://www.w3.org/TR/NOTE-datetime">ISO 8601</a> * complete date formatted as {@code "%tY-%tm-%td"}. * * <tr><th scope="row" style="vertical-align:top">{@code 'c'} * <td> Date and time formatted as {@code "%ta %tb %td %tT %tZ %tY"}, * e.g. {@code "Sun Jul 20 16:17:00 EDT 1969"}. * * </tbody> * </table> * * <p> Any characters not explicitly defined as date/time conversion suffixes * are illegal and are reserved for future extensions. * * <h3> Flags </h3> * * <p> The following table summarizes the supported flags. <i>y</i> means the * flag is supported for the indicated argument types. * * <table class="striped"> * <caption style="display:none">genConv</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Flag <th scope="col" style="vertical-align:bottom"> General * <th scope="col" style="vertical-align:bottom"> Character <th scope="col" style="vertical-align:bottom"> Integral * <th scope="col" style="vertical-align:bottom"> Floating Point * <th scope="col" style="vertical-align:bottom"> Date/Time * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * <tr><th scope="row"> '-' <td style="text-align:center; vertical-align:top"> y * <td style="text-align:center; vertical-align:top"> y * <td style="text-align:center; vertical-align:top"> y * <td style="text-align:center; vertical-align:top"> y * <td style="text-align:center; vertical-align:top"> y * <td> The result will be left-justified. * * <tr><th scope="row"> '#' <td style="text-align:center; vertical-align:top"> y<sup>1</sup> * <td style="text-align:center; vertical-align:top"> - * <td style="text-align:center; vertical-align:top"> y<sup>3</sup> * <td style="text-align:center; vertical-align:top"> y * <td style="text-align:center; vertical-align:top"> - * <td> The result should use a conversion-dependent alternate form * * <tr><th scope="row"> '+' <td style="text-align:center; vertical-align:top"> - * <td style="text-align:center; vertical-align:top"> - * <td style="text-align:center; vertical-align:top"> y<sup>4</sup> * <td style="text-align:center; vertical-align:top"> y * <td style="text-align:center; vertical-align:top"> - * <td> The result will always include a sign * * <tr><th scope="row"> ' ' <td style="text-align:center; vertical-align:top"> - * <td style="text-align:center; vertical-align:top"> - * <td style="text-align:center; vertical-align:top"> y<sup>4</sup> * <td style="text-align:center; vertical-align:top"> y * <td style="text-align:center; vertical-align:top"> - * <td> The result will include a leading space for positive values * * <tr><th scope="row"> '0' <td style="text-align:center; vertical-align:top"> - * <td style="text-align:center; vertical-align:top"> - * <td style="text-align:center; vertical-align:top"> y * <td style="text-align:center; vertical-align:top"> y * <td style="text-align:center; vertical-align:top"> - * <td> The result will be zero-padded * * <tr><th scope="row"> ',' <td style="text-align:center; vertical-align:top"> - * <td style="text-align:center; vertical-align:top"> - * <td style="text-align:center; vertical-align:top"> y<sup>2</sup> * <td style="text-align:center; vertical-align:top"> y<sup>5</sup> * <td style="text-align:center; vertical-align:top"> - * <td> The result will include locale-specific {@linkplain * java.text.DecimalFormatSymbols#getGroupingSeparator grouping separators} * * <tr><th scope="row"> '(' <td style="text-align:center; vertical-align:top"> - * <td style="text-align:center; vertical-align:top"> - * <td style="text-align:center; vertical-align:top"> y<sup>4</sup> * <td style="text-align:center; vertical-align:top"> y<sup>5</sup> * <td style="text-align:center"> - * <td> The result will enclose negative numbers in parentheses * * </tbody> * </table> * * <p> <sup>1</sup> Depends on the definition of {@link Formattable}. * * <p> <sup>2</sup> For {@code 'd'} conversion only. * * <p> <sup>3</sup> For {@code 'o'}, {@code 'x'}, and {@code 'X'} * conversions only. * * <p> <sup>4</sup> For {@code 'd'}, {@code 'o'}, {@code 'x'}, and * {@code 'X'} conversions applied to {@link java.math.BigInteger BigInteger} * or {@code 'd'} applied to {@code byte}, {@link Byte}, {@code short}, {@link * Short}, {@code int} and {@link Integer}, {@code long}, and {@link Long}. * * <p> <sup>5</sup> For {@code 'e'}, {@code 'E'}, {@code 'f'}, * {@code 'g'}, and {@code 'G'} conversions only. * * <p> Any characters not explicitly defined as flags are illegal and are * reserved for future extensions. * * <h3> Width </h3> * * <p> The width is the minimum number of characters to be written to the * output. For the line separator conversion, width is not applicable; if it * is provided, an exception will be thrown. * * <h3> Precision </h3> * * <p> For general argument types, the precision is the maximum number of * characters to be written to the output. * * <p> For the floating-point conversions {@code 'a'}, {@code 'A'}, {@code 'e'}, * {@code 'E'}, and {@code 'f'} the precision is the number of digits after the * radix point. If the conversion is {@code 'g'} or {@code 'G'}, then the * precision is the total number of digits in the resulting magnitude after * rounding. * * <p> For character, integral, and date/time argument types and the percent * and line separator conversions, the precision is not applicable; if a * precision is provided, an exception will be thrown. * * <h3> Argument Index </h3> * * <p> The argument index is a decimal integer indicating the position of the * argument in the argument list. The first argument is referenced by * "{@code 1$}", the second by "{@code 2$}", etc. * * <p> Another way to reference arguments by position is to use the * {@code '<'} (<code>'\u003c'</code>) flag, which causes the argument for * the previous format specifier to be re-used. For example, the following two * statements would produce identical strings: * * <blockquote><pre> * Calendar c = ...; * String s1 = String.format("Duke's Birthday: %1$tm %1$te,%1$tY", c); * * String s2 = String.format("Duke's Birthday: %1$tm %<te,%<tY", c); * </pre></blockquote> * * <hr> * <h2><a id="detail">Details</a></h2> * * <p> This section is intended to provide behavioral details for formatting, * including conditions and exceptions, supported data types, localization, and * interactions between flags, conversions, and data types. For an overview of * formatting concepts, refer to the <a href="#summary">Summary</a> * * <p> Any characters not explicitly defined as conversions, date/time * conversion suffixes, or flags are illegal and are reserved for * future extensions. Use of such a character in a format string will * cause an {@link UnknownFormatConversionException} or {@link * UnknownFormatFlagsException} to be thrown. * * <p> If the format specifier contains a width or precision with an invalid * value or which is otherwise unsupported, then a {@link * IllegalFormatWidthException} or {@link IllegalFormatPrecisionException} * respectively will be thrown. Similarly, values of zero for an argument * index will result in an {@link IllegalFormatException}. * * <p> If a format specifier contains a conversion character that is not * applicable to the corresponding argument, then an {@link * IllegalFormatConversionException} will be thrown. * * <p> Values of <i>precision</i> must be in the range zero to * {@link Integer#MAX_VALUE}, inclusive, otherwise * {@link IllegalFormatPrecisionException} is thrown.</p> * * <p> Values of <i>width</i> must be in the range one to * {@link Integer#MAX_VALUE}, inclusive, otherwise * {@link IllegalFormatWidthException} will be thrown * Note that widths can appear to have a negative value, but the negative sign * is a <i>flag</i>. For example in the format string {@code "%-20s"} the * <i>width</i> is <i>20</i> and the <i>flag</i> is "-".</p> * * <p> Values of <i>index</i> must be in the range one to * {@link Integer#MAX_VALUE}, inclusive, otherwise * {@link IllegalFormatException} will be thrown.</p> * * <p> All specified exceptions may be thrown by any of the {@code format} * methods of {@code Formatter} as well as by any {@code format} convenience * methods such as {@link String#format(String,Object...) String.format} and * {@link java.io.PrintStream#printf(String,Object...) PrintStream.printf}. * * <p> For category <i>General</i>, <i>Character</i>, <i>Numeric</i>, * <i>Integral</i> and <i>Date/Time</i> conversion, unless otherwise specified, * if the argument <i>arg</i> is {@code null}, then the result is "{@code null}". * * <p> Conversions denoted by an upper-case character (i.e. {@code 'B'}, * {@code 'H'}, {@code 'S'}, {@code 'C'}, {@code 'X'}, {@code 'E'}, * {@code 'G'}, {@code 'A'}, and {@code 'T'}) are the same as those for the * corresponding lower-case conversion characters except that the result is * converted to upper case according to the rules of the prevailing {@link * java.util.Locale Locale}. If there is no explicit locale specified, * either at the construction of the instance or as a parameter to its method * invocation, then the {@link java.util.Locale.Category#FORMAT default locale} * is used. * * <h3><a id="dgen">General</a></h3> * * <p> The following general conversions may be applied to any argument type: * * <table class="striped"> * <caption style="display:none">dgConv</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Unicode * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top"> {@code 'b'} * <td style="vertical-align:top"> <code>'\u0062'</code> * <td> Produces either "{@code true}" or "{@code false}" as returned by * {@link Boolean#toString(boolean)}. * * <p> If the argument is {@code null}, then the result is * "{@code false}". If the argument is a {@code boolean} or {@link * Boolean}, then the result is the string returned by {@link * String#valueOf(boolean) String.valueOf()}. Otherwise, the result is * "{@code true}". * * <p> If the {@code '#'} flag is given, then a {@link * FormatFlagsConversionMismatchException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'B'} * <td style="vertical-align:top"> <code>'\u0042'</code> * <td> The upper-case variant of {@code 'b'}. * * <tr><th scope="row" style="vertical-align:top"> {@code 'h'} * <td style="vertical-align:top"> <code>'\u0068'</code> * <td> Produces a string representing the hash code value of the object. * * <p> The result is obtained by invoking * {@code Integer.toHexString(arg.hashCode())}. * * <p> If the {@code '#'} flag is given, then a {@link * FormatFlagsConversionMismatchException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'H'} * <td style="vertical-align:top"> <code>'\u0048'</code> * <td> The upper-case variant of {@code 'h'}. * * <tr><th scope="row" style="vertical-align:top"> {@code 's'} * <td style="vertical-align:top"> <code>'\u0073'</code> * <td> Produces a string. * * <p> If the argument implements {@link Formattable}, then * its {@link Formattable#formatTo formatTo} method is invoked. * Otherwise, the result is obtained by invoking the argument's * {@code toString()} method. * * <p> If the {@code '#'} flag is given and the argument is not a {@link * Formattable}, then a {@link FormatFlagsConversionMismatchException} * will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'S'} * <td style="vertical-align:top"> <code>'\u0053'</code> * <td> The upper-case variant of {@code 's'}. * * </tbody> * </table> * * <p> The following <a id="dFlags">flags</a> apply to general conversions: * * <table class="striped"> * <caption style="display:none">dFlags</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Flag * <th scope="col" style="vertical-align:bottom"> Unicode * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top"> {@code '-'} * <td style="vertical-align:top"> <code>'\u002d'</code> * <td> Left justifies the output. Spaces (<code>'\u0020'</code>) will be * added at the end of the converted value as required to fill the minimum * width of the field. If the width is not provided, then a {@link * MissingFormatWidthException} will be thrown. If this flag is not given * then the output will be right-justified. * * <tr><th scope="row" style="vertical-align:top"> {@code '#'} * <td style="vertical-align:top"> <code>'\u0023'</code> * <td> Requires the output use an alternate form. The definition of the * form is specified by the conversion. * * </tbody> * </table> * * <p> The <a id="genWidth">width</a> is the minimum number of characters to * be written to the * output. If the length of the converted value is less than the width then * the output will be padded by <code>' '</code> (<code>'\u0020'</code>) * until the total number of characters equals the width. The padding is on * the left by default. If the {@code '-'} flag is given, then the padding * will be on the right. If the width is not specified then there is no * minimum. * * <p> The precision is the maximum number of characters to be written to the * output. The precision is applied before the width, thus the output will be * truncated to {@code precision} characters even if the width is greater than * the precision. If the precision is not specified then there is no explicit * limit on the number of characters. * * <h3><a id="dchar">Character</a></h3> * * This conversion may be applied to {@code char} and {@link Character}. It * may also be applied to the types {@code byte}, {@link Byte}, * {@code short}, and {@link Short}, {@code int} and {@link Integer} when * {@link Character#isValidCodePoint} returns {@code true}. If it returns * {@code false} then an {@link IllegalFormatCodePointException} will be * thrown. * * <table class="striped"> * <caption style="display:none">charConv</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Unicode * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top"> {@code 'c'} * <td style="vertical-align:top"> <code>'\u0063'</code> * <td> Formats the argument as a Unicode character as described in <a * href="../lang/Character.html#unicode">Unicode Character * Representation</a>. This may be more than one 16-bit {@code char} in * the case where the argument represents a supplementary character. * * <p> If the {@code '#'} flag is given, then a {@link * FormatFlagsConversionMismatchException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'C'} * <td style="vertical-align:top"> <code>'\u0043'</code> * <td> The upper-case variant of {@code 'c'}. * * </tbody> * </table> * * <p> The {@code '-'} flag defined for <a href="#dFlags">General * conversions</a> applies. If the {@code '#'} flag is given, then a {@link * FormatFlagsConversionMismatchException} will be thrown. * * <p> The width is defined as for <a href="#genWidth">General conversions</a>. * * <p> The precision is not applicable. If the precision is specified then an * {@link IllegalFormatPrecisionException} will be thrown. * * <h3><a id="dnum">Numeric</a></h3> * * <p> Numeric conversions are divided into the following categories: * * <ol> * * <li> <a href="#dnint"><b>Byte, Short, Integer, and Long</b></a> * * <li> <a href="#dnbint"><b>BigInteger</b></a> * * <li> <a href="#dndec"><b>Float and Double</b></a> * * <li> <a href="#dnbdec"><b>BigDecimal</b></a> * * </ol> * * <p> Numeric types will be formatted according to the following algorithm: * * <p><b><a id="L10nAlgorithm"> Number Localization Algorithm</a></b> * * <p> After digits are obtained for the integer part, fractional part, and * exponent (as appropriate for the data type), the following transformation * is applied: * * <ol> * * <li> Each digit character <i>d</i> in the string is replaced by a * locale-specific digit computed relative to the current locale's * {@linkplain java.text.DecimalFormatSymbols#getZeroDigit() zero digit} * <i>z</i>; that is <i>d - </i> {@code '0'} * <i> + z</i>. * * <li> If a decimal separator is present, a locale-specific {@linkplain * java.text.DecimalFormatSymbols#getDecimalSeparator decimal separator} is * substituted. * * <li> If the {@code ','} (<code>'\u002c'</code>) * <a id="L10nGroup">flag</a> is given, then the locale-specific {@linkplain * java.text.DecimalFormatSymbols#getGroupingSeparator grouping separator} is * inserted by scanning the integer part of the string from least significant * to most significant digits and inserting a separator at intervals defined by * the locale's {@linkplain java.text.DecimalFormat#getGroupingSize() grouping * size}. * * <li> If the {@code '0'} flag is given, then the locale-specific {@linkplain * java.text.DecimalFormatSymbols#getZeroDigit() zero digits} are inserted * after the sign character, if any, and before the first non-zero digit, until * the length of the string is equal to the requested field width. * * <li> If the value is negative and the {@code '('} flag is given, then a * {@code '('} (<code>'\u0028'</code>) is prepended and a {@code ')'} * (<code>'\u0029'</code>) is appended. * * <li> If the value is negative (or floating-point negative zero) and * {@code '('} flag is not given, then a {@code '-'} (<code>'\u002d'</code>) * is prepended. * * <li> If the {@code '+'} flag is given and the value is positive or zero (or * floating-point positive zero), then a {@code '+'} (<code>'\u002b'</code>) * will be prepended. * * </ol> * * <p> If the value is NaN or positive infinity the literal strings "NaN" or * "Infinity" respectively, will be output. If the value is negative infinity, * then the output will be "(Infinity)" if the {@code '('} flag is given * otherwise the output will be "-Infinity". These values are not localized. * * <p><a id="dnint"><b> Byte, Short, Integer, and Long </b></a> * * <p> The following conversions may be applied to {@code byte}, {@link Byte}, * {@code short}, {@link Short}, {@code int} and {@link Integer}, * {@code long}, and {@link Long}. * * <table class="striped"> * <caption style="display:none">IntConv</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Unicode * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top"> {@code 'd'} * <td style="vertical-align:top"> <code>'\u0064'</code> * <td> Formats the argument as a decimal integer. The <a * href="#L10nAlgorithm">localization algorithm</a> is applied. * * <p> If the {@code '0'} flag is given and the value is negative, then * the zero padding will occur after the sign. * * <p> If the {@code '#'} flag is given then a {@link * FormatFlagsConversionMismatchException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'o'} * <td style="vertical-align:top"> <code>'\u006f'</code> * <td> Formats the argument as an integer in base eight. No localization * is applied. * * <p> If <i>x</i> is negative then the result will be an unsigned value * generated by adding 2<sup>n</sup> to the value where {@code n} is the * number of bits in the type as returned by the static {@code SIZE} field * in the {@linkplain Byte#SIZE Byte}, {@linkplain Short#SIZE Short}, * {@linkplain Integer#SIZE Integer}, or {@linkplain Long#SIZE Long} * classes as appropriate. * * <p> If the {@code '#'} flag is given then the output will always begin * with the radix indicator {@code '0'}. * * <p> If the {@code '0'} flag is given then the output will be padded * with leading zeros to the field width following any indication of sign. * * <p> If {@code '('}, {@code '+'}, ' ', or {@code ','} flags * are given then a {@link FormatFlagsConversionMismatchException} will be * thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'x'} * <td style="vertical-align:top"> <code>'\u0078'</code> * <td> Formats the argument as an integer in base sixteen. No * localization is applied. * * <p> If <i>x</i> is negative then the result will be an unsigned value * generated by adding 2<sup>n</sup> to the value where {@code n} is the * number of bits in the type as returned by the static {@code SIZE} field * in the {@linkplain Byte#SIZE Byte}, {@linkplain Short#SIZE Short}, * {@linkplain Integer#SIZE Integer}, or {@linkplain Long#SIZE Long} * classes as appropriate. * * <p> If the {@code '#'} flag is given then the output will always begin * with the radix indicator {@code "0x"}. * * <p> If the {@code '0'} flag is given then the output will be padded to * the field width with leading zeros after the radix indicator or sign (if * present). * * <p> If {@code '('}, <code>' '</code>, {@code '+'}, or * {@code ','} flags are given then a {@link * FormatFlagsConversionMismatchException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'X'} * <td style="vertical-align:top"> <code>'\u0058'</code> * <td> The upper-case variant of {@code 'x'}. The entire string * representing the number will be converted to {@linkplain * String#toUpperCase upper case} including the {@code 'x'} (if any) and * all hexadecimal digits {@code 'a'} - {@code 'f'} * (<code>'\u0061'</code> - <code>'\u0066'</code>). * * </tbody> * </table> * * <p> If the conversion is {@code 'o'}, {@code 'x'}, or {@code 'X'} and * both the {@code '#'} and the {@code '0'} flags are given, then result will * contain the radix indicator ({@code '0'} for octal and {@code "0x"} or * {@code "0X"} for hexadecimal), some number of zeros (based on the width), * and the value. * * <p> If the {@code '-'} flag is not given, then the space padding will occur * before the sign. * * <p> The following <a id="intFlags">flags</a> apply to numeric integral * conversions: * * <table class="striped"> * <caption style="display:none">intFlags</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Unicode * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top"> {@code '+'} * <td style="vertical-align:top"> <code>'\u002b'</code> * <td> Requires the output to include a positive sign for all positive * numbers. If this flag is not given then only negative values will * include a sign. * * <p> If both the {@code '+'} and <code>' '</code> flags are given * then an {@link IllegalFormatFlagsException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> <code>' '</code> * <td style="vertical-align:top"> <code>'\u0020'</code> * <td> Requires the output to include a single extra space * (<code>'\u0020'</code>) for non-negative values. * * <p> If both the {@code '+'} and <code>' '</code> flags are given * then an {@link IllegalFormatFlagsException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code '0'} * <td style="vertical-align:top"> <code>'\u0030'</code> * <td> Requires the output to be padded with leading {@linkplain * java.text.DecimalFormatSymbols#getZeroDigit zeros} to the minimum field * width following any sign or radix indicator except when converting NaN * or infinity. If the width is not provided, then a {@link * MissingFormatWidthException} will be thrown. * * <p> If both the {@code '-'} and {@code '0'} flags are given then an * {@link IllegalFormatFlagsException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code ','} * <td style="vertical-align:top"> <code>'\u002c'</code> * <td> Requires the output to include the locale-specific {@linkplain * java.text.DecimalFormatSymbols#getGroupingSeparator group separators} as * described in the <a href="#L10nGroup">"group" section</a> of the * localization algorithm. * * <tr><th scope="row" style="vertical-align:top"> {@code '('} * <td style="vertical-align:top"> <code>'\u0028'</code> * <td> Requires the output to prepend a {@code '('} * (<code>'\u0028'</code>) and append a {@code ')'} * (<code>'\u0029'</code>) to negative values. * * </tbody> * </table> * * <p> If no <a id="intdFlags">flags</a> are given the default formatting is * as follows: * * <ul> * * <li> The output is right-justified within the {@code width} * * <li> Negative numbers begin with a {@code '-'} (<code>'\u002d'</code>) * * <li> Positive numbers and zero do not include a sign or extra leading * space * * <li> No grouping separators are included * * </ul> * * <p> The <a id="intWidth">width</a> is the minimum number of characters to * be written to the output. This includes any signs, digits, grouping * separators, radix indicator, and parentheses. If the length of the * converted value is less than the width then the output will be padded by * spaces (<code>'\u0020'</code>) until the total number of characters equals * width. The padding is on the left by default. If {@code '-'} flag is * given then the padding will be on the right. If width is not specified then * there is no minimum. * * <p> The precision is not applicable. If precision is specified then an * {@link IllegalFormatPrecisionException} will be thrown. * * <p><a id="dnbint"><b> BigInteger </b></a> * * <p> The following conversions may be applied to {@link * java.math.BigInteger}. * * <table class="striped"> * <caption style="display:none">bIntConv</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Unicode * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top"> {@code 'd'} * <td style="vertical-align:top"> <code>'\u0064'</code> * <td> Requires the output to be formatted as a decimal integer. The <a * href="#L10nAlgorithm">localization algorithm</a> is applied. * * <p> If the {@code '#'} flag is given {@link * FormatFlagsConversionMismatchException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'o'} * <td style="vertical-align:top"> <code>'\u006f'</code> * <td> Requires the output to be formatted as an integer in base eight. * No localization is applied. * * <p> If <i>x</i> is negative then the result will be a signed value * beginning with {@code '-'} (<code>'\u002d'</code>). Signed output is * allowed for this type because unlike the primitive types it is not * possible to create an unsigned equivalent without assuming an explicit * data-type size. * * <p> If <i>x</i> is positive or zero and the {@code '+'} flag is given * then the result will begin with {@code '+'} (<code>'\u002b'</code>). * * <p> If the {@code '#'} flag is given then the output will always begin * with {@code '0'} prefix. * * <p> If the {@code '0'} flag is given then the output will be padded * with leading zeros to the field width following any indication of sign. * * <p> If the {@code ','} flag is given then a {@link * FormatFlagsConversionMismatchException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'x'} * <td style="vertical-align:top"> <code>'\u0078'</code> * <td> Requires the output to be formatted as an integer in base * sixteen. No localization is applied. * * <p> If <i>x</i> is negative then the result will be a signed value * beginning with {@code '-'} (<code>'\u002d'</code>). Signed output is * allowed for this type because unlike the primitive types it is not * possible to create an unsigned equivalent without assuming an explicit * data-type size. * * <p> If <i>x</i> is positive or zero and the {@code '+'} flag is given * then the result will begin with {@code '+'} (<code>'\u002b'</code>). * * <p> If the {@code '#'} flag is given then the output will always begin * with the radix indicator {@code "0x"}. * * <p> If the {@code '0'} flag is given then the output will be padded to * the field width with leading zeros after the radix indicator or sign (if * present). * * <p> If the {@code ','} flag is given then a {@link * FormatFlagsConversionMismatchException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'X'} * <td style="vertical-align:top"> <code>'\u0058'</code> * <td> The upper-case variant of {@code 'x'}. The entire string * representing the number will be converted to {@linkplain * String#toUpperCase upper case} including the {@code 'x'} (if any) and * all hexadecimal digits {@code 'a'} - {@code 'f'} * (<code>'\u0061'</code> - <code>'\u0066'</code>). * * </tbody> * </table> * * <p> If the conversion is {@code 'o'}, {@code 'x'}, or {@code 'X'} and * both the {@code '#'} and the {@code '0'} flags are given, then result will * contain the base indicator ({@code '0'} for octal and {@code "0x"} or * {@code "0X"} for hexadecimal), some number of zeros (based on the width), * and the value. * * <p> If the {@code '0'} flag is given and the value is negative, then the * zero padding will occur after the sign. * * <p> If the {@code '-'} flag is not given, then the space padding will occur * before the sign. * * <p> All <a href="#intFlags">flags</a> defined for Byte, Short, Integer, and * Long apply. The <a href="#intdFlags">default behavior</a> when no flags are * given is the same as for Byte, Short, Integer, and Long. * * <p> The specification of <a href="#intWidth">width</a> is the same as * defined for Byte, Short, Integer, and Long. * * <p> The precision is not applicable. If precision is specified then an * {@link IllegalFormatPrecisionException} will be thrown. * * <p><a id="dndec"><b> Float and Double</b></a> * * <p> The following conversions may be applied to {@code float}, {@link * Float}, {@code double} and {@link Double}. * * <table class="striped"> * <caption style="display:none">floatConv</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Unicode * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top"> {@code 'e'} * <td style="vertical-align:top"> <code>'\u0065'</code> * <td> Requires the output to be formatted using <a * id="scientific">computerized scientific notation</a>. The <a * href="#L10nAlgorithm">localization algorithm</a> is applied. * * <p> The formatting of the magnitude <i>m</i> depends upon its value. * * <p> If <i>m</i> is NaN or infinite, the literal strings "NaN" or * "Infinity", respectively, will be output. These values are not * localized. * * <p> If <i>m</i> is positive-zero or negative-zero, then the exponent * will be {@code "+00"}. * * <p> Otherwise, the result is a string that represents the sign and * magnitude (absolute value) of the argument. The formatting of the sign * is described in the <a href="#L10nAlgorithm">localization * algorithm</a>. The formatting of the magnitude <i>m</i> depends upon its * value. * * <p> Let <i>n</i> be the unique integer such that 10<sup><i>n</i></sup> * <= <i>m</i> < 10<sup><i>n</i>+1</sup>; then let <i>a</i> be the * mathematically exact quotient of <i>m</i> and 10<sup><i>n</i></sup> so * that 1 <= <i>a</i> < 10. The magnitude is then represented as the * integer part of <i>a</i>, as a single decimal digit, followed by the * decimal separator followed by decimal digits representing the fractional * part of <i>a</i>, followed by the exponent symbol {@code 'e'} * (<code>'\u0065'</code>), followed by the sign of the exponent, followed * by a representation of <i>n</i> as a decimal integer, as produced by the * method {@link Long#toString(long, int)}, and zero-padded to include at * least two digits. * * <p> The number of digits in the result for the fractional part of * <i>m</i> or <i>a</i> is equal to the precision. If the precision is not * specified then the default value is {@code 6}. If the precision is less * than the number of digits which would appear after the decimal point in * the string returned by {@link Float#toString(float)} or {@link * Double#toString(double)} respectively, then the value will be rounded * using the {@linkplain java.math.RoundingMode#HALF_UP round half up * algorithm}. Otherwise, zeros may be appended to reach the precision. * For a canonical representation of the value, use {@link * Float#toString(float)} or {@link Double#toString(double)} as * appropriate. * * <p>If the {@code ','} flag is given, then an {@link * FormatFlagsConversionMismatchException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'E'} * <td style="vertical-align:top"> <code>'\u0045'</code> * <td> The upper-case variant of {@code 'e'}. The exponent symbol * will be {@code 'E'} (<code>'\u0045'</code>). * * <tr><th scope="row" style="vertical-align:top"> {@code 'g'} * <td style="vertical-align:top"> <code>'\u0067'</code> * <td> Requires the output to be formatted in general scientific notation * as described below. The <a href="#L10nAlgorithm">localization * algorithm</a> is applied. * * <p> After rounding for the precision, the formatting of the resulting * magnitude <i>m</i> depends on its value. * * <p> If <i>m</i> is greater than or equal to 10<sup>-4</sup> but less * than 10<sup>precision</sup> then it is represented in <i><a * href="#decimal">decimal format</a></i>. * * <p> If <i>m</i> is less than 10<sup>-4</sup> or greater than or equal to * 10<sup>precision</sup>, then it is represented in <i><a * href="#scientific">computerized scientific notation</a></i>. * * <p> The total number of significant digits in <i>m</i> is equal to the * precision. If the precision is not specified, then the default value is * {@code 6}. If the precision is {@code 0}, then it is taken to be * {@code 1}. * * <p> If the {@code '#'} flag is given then an {@link * FormatFlagsConversionMismatchException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'G'} * <td style="vertical-align:top"> <code>'\u0047'</code> * <td> The upper-case variant of {@code 'g'}. * * <tr><th scope="row" style="vertical-align:top"> {@code 'f'} * <td style="vertical-align:top"> <code>'\u0066'</code> * <td> Requires the output to be formatted using <a id="decimal">decimal * format</a>. The <a href="#L10nAlgorithm">localization algorithm</a> is * applied. * * <p> The result is a string that represents the sign and magnitude * (absolute value) of the argument. The formatting of the sign is * described in the <a href="#L10nAlgorithm">localization * algorithm</a>. The formatting of the magnitude <i>m</i> depends upon its * value. * * <p> If <i>m</i> NaN or infinite, the literal strings "NaN" or * "Infinity", respectively, will be output. These values are not * localized. * * <p> The magnitude is formatted as the integer part of <i>m</i>, with no * leading zeroes, followed by the decimal separator followed by one or * more decimal digits representing the fractional part of <i>m</i>. * * <p> The number of digits in the result for the fractional part of * <i>m</i> or <i>a</i> is equal to the precision. If the precision is not * specified then the default value is {@code 6}. If the precision is less * than the number of digits which would appear after the decimal point in * the string returned by {@link Float#toString(float)} or {@link * Double#toString(double)} respectively, then the value will be rounded * using the {@linkplain java.math.RoundingMode#HALF_UP round half up * algorithm}. Otherwise, zeros may be appended to reach the precision. * For a canonical representation of the value, use {@link * Float#toString(float)} or {@link Double#toString(double)} as * appropriate. * * <tr><th scope="row" style="vertical-align:top"> {@code 'a'} * <td style="vertical-align:top"> <code>'\u0061'</code> * <td> Requires the output to be formatted in hexadecimal exponential * form. No localization is applied. * * <p> The result is a string that represents the sign and magnitude * (absolute value) of the argument <i>x</i>. * * <p> If <i>x</i> is negative or a negative-zero value then the result * will begin with {@code '-'} (<code>'\u002d'</code>). * * <p> If <i>x</i> is positive or a positive-zero value and the * {@code '+'} flag is given then the result will begin with {@code '+'} * (<code>'\u002b'</code>). * * <p> The formatting of the magnitude <i>m</i> depends upon its value. * * <ul> * * <li> If the value is NaN or infinite, the literal strings "NaN" or * "Infinity", respectively, will be output. * * <li> If <i>m</i> is zero then it is represented by the string * {@code "0x0.0p0"}. * * <li> If <i>m</i> is a {@code double} value with a normalized * representation then substrings are used to represent the significand and * exponent fields. The significand is represented by the characters * {@code "0x1."} followed by the hexadecimal representation of the rest * of the significand as a fraction. The exponent is represented by * {@code 'p'} (<code>'\u0070'</code>) followed by a decimal string of the * unbiased exponent as if produced by invoking {@link * Integer#toString(int) Integer.toString} on the exponent value. If the * precision is specified, the value is rounded to the given number of * hexadecimal digits. * * <li> If <i>m</i> is a {@code double} value with a subnormal * representation then, unless the precision is specified to be in the range * 1 through 12, inclusive, the significand is represented by the characters * {@code '0x0.'} followed by the hexadecimal representation of the rest of * the significand as a fraction, and the exponent represented by * {@code 'p-1022'}. If the precision is in the interval * [1, 12], the subnormal value is normalized such that it * begins with the characters {@code '0x1.'}, rounded to the number of * hexadecimal digits of precision, and the exponent adjusted * accordingly. Note that there must be at least one nonzero digit in a * subnormal significand. * * </ul> * * <p> If the {@code '('} or {@code ','} flags are given, then a {@link * FormatFlagsConversionMismatchException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'A'} * <td style="vertical-align:top"> <code>'\u0041'</code> * <td> The upper-case variant of {@code 'a'}. The entire string * representing the number will be converted to upper case including the * {@code 'x'} (<code>'\u0078'</code>) and {@code 'p'} * (<code>'\u0070'</code> and all hexadecimal digits {@code 'a'} - * {@code 'f'} (<code>'\u0061'</code> - <code>'\u0066'</code>). * * </tbody> * </table> * * <p> All <a href="#intFlags">flags</a> defined for Byte, Short, Integer, and * Long apply. * * <p> If the {@code '#'} flag is given, then the decimal separator will * always be present. * * <p> If no <a id="floatdFlags">flags</a> are given the default formatting * is as follows: * * <ul> * * <li> The output is right-justified within the {@code width} * * <li> Negative numbers begin with a {@code '-'} * * <li> Positive numbers and positive zero do not include a sign or extra * leading space * * <li> No grouping separators are included * * <li> The decimal separator will only appear if a digit follows it * * </ul> * * <p> The <a id="floatDWidth">width</a> is the minimum number of characters * to be written to the output. This includes any signs, digits, grouping * separators, decimal separators, exponential symbol, radix indicator, * parentheses, and strings representing infinity and NaN as applicable. If * the length of the converted value is less than the width then the output * will be padded by spaces (<code>'\u0020'</code>) until the total number of * characters equals width. The padding is on the left by default. If the * {@code '-'} flag is given then the padding will be on the right. If width * is not specified then there is no minimum. * * <p> If the <a id="floatDPrec">conversion</a> is {@code 'e'}, * {@code 'E'} or {@code 'f'}, then the precision is the number of digits * after the decimal separator. If the precision is not specified, then it is * assumed to be {@code 6}. * * <p> If the conversion is {@code 'g'} or {@code 'G'}, then the precision is * the total number of significant digits in the resulting magnitude after * rounding. If the precision is not specified, then the default value is * {@code 6}. If the precision is {@code 0}, then it is taken to be * {@code 1}. * * <p> If the conversion is {@code 'a'} or {@code 'A'}, then the precision * is the number of hexadecimal digits after the radix point. If the * precision is not provided, then all of the digits as returned by {@link * Double#toHexString(double)} will be output. * * <p><a id="dnbdec"><b> BigDecimal </b></a> * * <p> The following conversions may be applied {@link java.math.BigDecimal * BigDecimal}. * * <table class="striped"> * <caption style="display:none">floatConv</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Unicode * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top"> {@code 'e'} * <td style="vertical-align:top"> <code>'\u0065'</code> * <td> Requires the output to be formatted using <a * id="bscientific">computerized scientific notation</a>. The <a * href="#L10nAlgorithm">localization algorithm</a> is applied. * * <p> The formatting of the magnitude <i>m</i> depends upon its value. * * <p> If <i>m</i> is positive-zero or negative-zero, then the exponent * will be {@code "+00"}. * * <p> Otherwise, the result is a string that represents the sign and * magnitude (absolute value) of the argument. The formatting of the sign * is described in the <a href="#L10nAlgorithm">localization * algorithm</a>. The formatting of the magnitude <i>m</i> depends upon its * value. * * <p> Let <i>n</i> be the unique integer such that 10<sup><i>n</i></sup> * <= <i>m</i> < 10<sup><i>n</i>+1</sup>; then let <i>a</i> be the * mathematically exact quotient of <i>m</i> and 10<sup><i>n</i></sup> so * that 1 <= <i>a</i> < 10. The magnitude is then represented as the * integer part of <i>a</i>, as a single decimal digit, followed by the * decimal separator followed by decimal digits representing the fractional * part of <i>a</i>, followed by the exponent symbol {@code 'e'} * (<code>'\u0065'</code>), followed by the sign of the exponent, followed * by a representation of <i>n</i> as a decimal integer, as produced by the * method {@link Long#toString(long, int)}, and zero-padded to include at * least two digits. * * <p> The number of digits in the result for the fractional part of * <i>m</i> or <i>a</i> is equal to the precision. If the precision is not * specified then the default value is {@code 6}. If the precision is * less than the number of digits to the right of the decimal point then * the value will be rounded using the * {@linkplain java.math.RoundingMode#HALF_UP round half up * algorithm}. Otherwise, zeros may be appended to reach the precision. * For a canonical representation of the value, use {@link * BigDecimal#toString()}. * * <p> If the {@code ','} flag is given, then an {@link * FormatFlagsConversionMismatchException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'E'} * <td style="vertical-align:top"> <code>'\u0045'</code> * <td> The upper-case variant of {@code 'e'}. The exponent symbol * will be {@code 'E'} (<code>'\u0045'</code>). * * <tr><th scope="row" style="vertical-align:top"> {@code 'g'} * <td style="vertical-align:top"> <code>'\u0067'</code> * <td> Requires the output to be formatted in general scientific notation * as described below. The <a href="#L10nAlgorithm">localization * algorithm</a> is applied. * * <p> After rounding for the precision, the formatting of the resulting * magnitude <i>m</i> depends on its value. * * <p> If <i>m</i> is greater than or equal to 10<sup>-4</sup> but less * than 10<sup>precision</sup> then it is represented in <i><a * href="#bdecimal">decimal format</a></i>. * * <p> If <i>m</i> is less than 10<sup>-4</sup> or greater than or equal to * 10<sup>precision</sup>, then it is represented in <i><a * href="#bscientific">computerized scientific notation</a></i>. * * <p> The total number of significant digits in <i>m</i> is equal to the * precision. If the precision is not specified, then the default value is * {@code 6}. If the precision is {@code 0}, then it is taken to be * {@code 1}. * * <p> If the {@code '#'} flag is given then an {@link * FormatFlagsConversionMismatchException} will be thrown. * * <tr><th scope="row" style="vertical-align:top"> {@code 'G'} * <td style="vertical-align:top"> <code>'\u0047'</code> * <td> The upper-case variant of {@code 'g'}. * * <tr><th scope="row" style="vertical-align:top"> {@code 'f'} * <td style="vertical-align:top"> <code>'\u0066'</code> * <td> Requires the output to be formatted using <a id="bdecimal">decimal * format</a>. The <a href="#L10nAlgorithm">localization algorithm</a> is * applied. * * <p> The result is a string that represents the sign and magnitude * (absolute value) of the argument. The formatting of the sign is * described in the <a href="#L10nAlgorithm">localization * algorithm</a>. The formatting of the magnitude <i>m</i> depends upon its * value. * * <p> The magnitude is formatted as the integer part of <i>m</i>, with no * leading zeroes, followed by the decimal separator followed by one or * more decimal digits representing the fractional part of <i>m</i>. * * <p> The number of digits in the result for the fractional part of * <i>m</i> or <i>a</i> is equal to the precision. If the precision is not * specified then the default value is {@code 6}. If the precision is * less than the number of digits to the right of the decimal point * then the value will be rounded using the * {@linkplain java.math.RoundingMode#HALF_UP round half up * algorithm}. Otherwise, zeros may be appended to reach the precision. * For a canonical representation of the value, use {@link * BigDecimal#toString()}. * * </tbody> * </table> * * <p> All <a href="#intFlags">flags</a> defined for Byte, Short, Integer, and * Long apply. * * <p> If the {@code '#'} flag is given, then the decimal separator will * always be present. * * <p> The <a href="#floatdFlags">default behavior</a> when no flags are * given is the same as for Float and Double. * * <p> The specification of <a href="#floatDWidth">width</a> and <a * href="#floatDPrec">precision</a> is the same as defined for Float and * Double. * * <h3><a id="ddt">Date/Time</a></h3> * * <p> This conversion may be applied to {@code long}, {@link Long}, {@link * Calendar}, {@link Date} and {@link TemporalAccessor TemporalAccessor} * * <table class="striped"> * <caption style="display:none">DTConv</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Unicode * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top"> {@code 't'} * <td style="vertical-align:top"> <code>'\u0074'</code> * <td> Prefix for date and time conversion characters. * <tr><th scope="row" style="vertical-align:top"> {@code 'T'} * <td style="vertical-align:top"> <code>'\u0054'</code> * <td> The upper-case variant of {@code 't'}. * * </tbody> * </table> * * <p> The following date and time conversion character suffixes are defined * for the {@code 't'} and {@code 'T'} conversions. The types are similar to * but not completely identical to those defined by GNU {@code date} and * POSIX {@code strftime(3c)}. Additional conversion types are provided to * access Java-specific functionality (e.g. {@code 'L'} for milliseconds * within the second). * * <p> The following conversion characters are used for formatting times: * * <table class="striped"> * <caption style="display:none">time</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Unicode * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top"> {@code 'H'} * <td style="vertical-align:top"> <code>'\u0048'</code> * <td> Hour of the day for the 24-hour clock, formatted as two digits with * a leading zero as necessary i.e. {@code 00 - 23}. {@code 00} * corresponds to midnight. * * <tr><th scope="row" style="vertical-align:top">{@code 'I'} * <td style="vertical-align:top"> <code>'\u0049'</code> * <td> Hour for the 12-hour clock, formatted as two digits with a leading * zero as necessary, i.e. {@code 01 - 12}. {@code 01} corresponds to * one o'clock (either morning or afternoon). * * <tr><th scope="row" style="vertical-align:top">{@code 'k'} * <td style="vertical-align:top"> <code>'\u006b'</code> * <td> Hour of the day for the 24-hour clock, i.e. {@code 0 - 23}. * {@code 0} corresponds to midnight. * * <tr><th scope="row" style="vertical-align:top">{@code 'l'} * <td style="vertical-align:top"> <code>'\u006c'</code> * <td> Hour for the 12-hour clock, i.e. {@code 1 - 12}. {@code 1} * corresponds to one o'clock (either morning or afternoon). * * <tr><th scope="row" style="vertical-align:top">{@code 'M'} * <td style="vertical-align:top"> <code>'\u004d'</code> * <td> Minute within the hour formatted as two digits with a leading zero * as necessary, i.e. {@code 00 - 59}. * * <tr><th scope="row" style="vertical-align:top">{@code 'S'} * <td style="vertical-align:top"> <code>'\u0053'</code> * <td> Seconds within the minute, formatted as two digits with a leading * zero as necessary, i.e. {@code 00 - 60} ("{@code 60}" is a special * value required to support leap seconds). * * <tr><th scope="row" style="vertical-align:top">{@code 'L'} * <td style="vertical-align:top"> <code>'\u004c'</code> * <td> Millisecond within the second formatted as three digits with * leading zeros as necessary, i.e. {@code 000 - 999}. * * <tr><th scope="row" style="vertical-align:top">{@code 'N'} * <td style="vertical-align:top"> <code>'\u004e'</code> * <td> Nanosecond within the second, formatted as nine digits with leading * zeros as necessary, i.e. {@code 000000000 - 999999999}. The precision * of this value is limited by the resolution of the underlying operating * system or hardware. * * <tr><th scope="row" style="vertical-align:top">{@code 'p'} * <td style="vertical-align:top"> <code>'\u0070'</code> * <td> Locale-specific {@linkplain * java.text.DateFormatSymbols#getAmPmStrings morning or afternoon} marker * in lower case, e.g."{@code am}" or "{@code pm}". Use of the * conversion prefix {@code 'T'} forces this output to upper case. (Note * that {@code 'p'} produces lower-case output. This is different from * GNU {@code date} and POSIX {@code strftime(3c)} which produce * upper-case output.) * * <tr><th scope="row" style="vertical-align:top">{@code 'z'} * <td style="vertical-align:top"> <code>'\u007a'</code> * <td> <a href="http://www.ietf.org/rfc/rfc0822.txt">RFC 822</a> * style numeric time zone offset from GMT, e.g. {@code -0800}. This * value will be adjusted as necessary for Daylight Saving Time. For * {@code long}, {@link Long}, and {@link Date} the time zone used is * the {@linkplain TimeZone#getDefault() default time zone} for this * instance of the Java virtual machine. * * <tr><th scope="row" style="vertical-align:top">{@code 'Z'} * <td style="vertical-align:top"> <code>'\u005a'</code> * <td> A string representing the abbreviation for the time zone. This * value will be adjusted as necessary for Daylight Saving Time. For * {@code long}, {@link Long}, and {@link Date} the time zone used is * the {@linkplain TimeZone#getDefault() default time zone} for this * instance of the Java virtual machine. The Formatter's locale will * supersede the locale of the argument (if any). * * <tr><th scope="row" style="vertical-align:top">{@code 's'} * <td style="vertical-align:top"> <code>'\u0073'</code> * <td> Seconds since the beginning of the epoch starting at 1 January 1970 * {@code 00:00:00} UTC, i.e. {@code Long.MIN_VALUE/1000} to * {@code Long.MAX_VALUE/1000}. * * <tr><th scope="row" style="vertical-align:top">{@code 'Q'} * <td style="vertical-align:top"> <code>'\u004f'</code> * <td> Milliseconds since the beginning of the epoch starting at 1 January * 1970 {@code 00:00:00} UTC, i.e. {@code Long.MIN_VALUE} to * {@code Long.MAX_VALUE}. The precision of this value is limited by * the resolution of the underlying operating system or hardware. * * </tbody> * </table> * * <p> The following conversion characters are used for formatting dates: * * <table class="striped"> * <caption style="display:none">date</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Unicode * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top">{@code 'B'} * <td style="vertical-align:top"> <code>'\u0042'</code> * <td> Locale-specific {@linkplain java.text.DateFormatSymbols#getMonths * full month name}, e.g. {@code "January"}, {@code "February"}. * * <tr><th scope="row" style="vertical-align:top">{@code 'b'} * <td style="vertical-align:top"> <code>'\u0062'</code> * <td> Locale-specific {@linkplain * java.text.DateFormatSymbols#getShortMonths abbreviated month name}, * e.g. {@code "Jan"}, {@code "Feb"}. * * <tr><th scope="row" style="vertical-align:top">{@code 'h'} * <td style="vertical-align:top"> <code>'\u0068'</code> * <td> Same as {@code 'b'}. * * <tr><th scope="row" style="vertical-align:top">{@code 'A'} * <td style="vertical-align:top"> <code>'\u0041'</code> * <td> Locale-specific full name of the {@linkplain * java.text.DateFormatSymbols#getWeekdays day of the week}, * e.g. {@code "Sunday"}, {@code "Monday"} * * <tr><th scope="row" style="vertical-align:top">{@code 'a'} * <td style="vertical-align:top"> <code>'\u0061'</code> * <td> Locale-specific short name of the {@linkplain * java.text.DateFormatSymbols#getShortWeekdays day of the week}, * e.g. {@code "Sun"}, {@code "Mon"} * * <tr><th scope="row" style="vertical-align:top">{@code 'C'} * <td style="vertical-align:top"> <code>'\u0043'</code> * <td> Four-digit year divided by {@code 100}, formatted as two digits * with leading zero as necessary, i.e. {@code 00 - 99} * * <tr><th scope="row" style="vertical-align:top">{@code 'Y'} * <td style="vertical-align:top"> <code>'\u0059'</code> <td> Year, formatted to at least * four digits with leading zeros as necessary, e.g. {@code 0092} equals * {@code 92} CE for the Gregorian calendar. * * <tr><th scope="row" style="vertical-align:top">{@code 'y'} * <td style="vertical-align:top"> <code>'\u0079'</code> * <td> Last two digits of the year, formatted with leading zeros as * necessary, i.e. {@code 00 - 99}. * * <tr><th scope="row" style="vertical-align:top">{@code 'j'} * <td style="vertical-align:top"> <code>'\u006a'</code> * <td> Day of year, formatted as three digits with leading zeros as * necessary, e.g. {@code 001 - 366} for the Gregorian calendar. * {@code 001} corresponds to the first day of the year. * * <tr><th scope="row" style="vertical-align:top">{@code 'm'} * <td style="vertical-align:top"> <code>'\u006d'</code> * <td> Month, formatted as two digits with leading zeros as necessary, * i.e. {@code 01 - 13}, where "{@code 01}" is the first month of the * year and ("{@code 13}" is a special value required to support lunar * calendars). * * <tr><th scope="row" style="vertical-align:top">{@code 'd'} * <td style="vertical-align:top"> <code>'\u0064'</code> * <td> Day of month, formatted as two digits with leading zeros as * necessary, i.e. {@code 01 - 31}, where "{@code 01}" is the first day * of the month. * * <tr><th scope="row" style="vertical-align:top">{@code 'e'} * <td style="vertical-align:top"> <code>'\u0065'</code> * <td> Day of month, formatted as two digits, i.e. {@code 1 - 31} where * "{@code 1}" is the first day of the month. * * </tbody> * </table> * * <p> The following conversion characters are used for formatting common * date/time compositions. * * <table class="striped"> * <caption style="display:none">composites</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Unicode * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top">{@code 'R'} * <td style="vertical-align:top"> <code>'\u0052'</code> * <td> Time formatted for the 24-hour clock as {@code "%tH:%tM"} * * <tr><th scope="row" style="vertical-align:top">{@code 'T'} * <td style="vertical-align:top"> <code>'\u0054'</code> * <td> Time formatted for the 24-hour clock as {@code "%tH:%tM:%tS"}. * * <tr><th scope="row" style="vertical-align:top">{@code 'r'} * <td style="vertical-align:top"> <code>'\u0072'</code> * <td> Time formatted for the 12-hour clock as {@code "%tI:%tM:%tS * %Tp"}. The location of the morning or afternoon marker * ({@code '%Tp'}) may be locale-dependent. * * <tr><th scope="row" style="vertical-align:top">{@code 'D'} * <td style="vertical-align:top"> <code>'\u0044'</code> * <td> Date formatted as {@code "%tm/%td/%ty"}. * * <tr><th scope="row" style="vertical-align:top">{@code 'F'} * <td style="vertical-align:top"> <code>'\u0046'</code> * <td> <a href="http://www.w3.org/TR/NOTE-datetime">ISO 8601</a> * complete date formatted as {@code "%tY-%tm-%td"}. * * <tr><th scope="row" style="vertical-align:top">{@code 'c'} * <td style="vertical-align:top"> <code>'\u0063'</code> * <td> Date and time formatted as {@code "%ta %tb %td %tT %tZ %tY"}, * e.g. {@code "Sun Jul 20 16:17:00 EDT 1969"}. * * </tbody> * </table> * * <p> The {@code '-'} flag defined for <a href="#dFlags">General * conversions</a> applies. If the {@code '#'} flag is given, then a {@link * FormatFlagsConversionMismatchException} will be thrown. * * <p> The width is the minimum number of characters to * be written to the output. If the length of the converted value is less than * the {@code width} then the output will be padded by spaces * (<code>'\u0020'</code>) until the total number of characters equals width. * The padding is on the left by default. If the {@code '-'} flag is given * then the padding will be on the right. If width is not specified then there * is no minimum. * * <p> The precision is not applicable. If the precision is specified then an * {@link IllegalFormatPrecisionException} will be thrown. * * <h3><a id="dper">Percent</a></h3> * * <p> The conversion does not correspond to any argument. * * <table class="striped"> * <caption style="display:none">DTConv</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top">{@code '%'} * <td> The result is a literal {@code '%'} (<code>'\u0025'</code>) * * <p> The width is the minimum number of characters to * be written to the output including the {@code '%'}. If the length of the * converted value is less than the {@code width} then the output will be * padded by spaces (<code>'\u0020'</code>) until the total number of * characters equals width. The padding is on the left. If width is not * specified then just the {@code '%'} is output. * * <p> The {@code '-'} flag defined for <a href="#dFlags">General * conversions</a> applies. If any other flags are provided, then a * {@link IllegalFormatFlagsException } will be thrown. * * <p> The precision is not applicable. If the precision is specified an * {@link IllegalFormatPrecisionException} will be thrown. * * </tbody> * </table> * * <h3><a id="dls">Line Separator</a></h3> * * <p> The conversion does not correspond to any argument. * * <table class="striped"> * <caption style="display:none">DTConv</caption> * <thead> * <tr><th scope="col" style="vertical-align:bottom"> Conversion * <th scope="col" style="vertical-align:bottom"> Description * </thead> * <tbody> * * <tr><th scope="row" style="vertical-align:top">{@code 'n'} * <td> the platform-specific line separator as returned by {@link * System#lineSeparator()}. * * </tbody> * </table> * * <p> Flags, width, and precision are not applicable. If any are provided an * {@link IllegalFormatFlagsException}, {@link IllegalFormatWidthException}, * and {@link IllegalFormatPrecisionException}, respectively will be thrown. * * <h3><a id="dpos">Argument Index</a></h3> * * <p> Format specifiers can reference arguments in three ways: * * <ul> * * <li> <i>Explicit indexing</i> is used when the format specifier contains an * argument index. The argument index is a decimal integer indicating the * position of the argument in the argument list. The first argument is * referenced by "{@code 1$}", the second by "{@code 2$}", etc. An argument * may be referenced more than once. * * <p> For example: * * <blockquote><pre> * formatter.format("%4$s %3$s %2$s %1$s %4$s %3$s %2$s %1$s", * "a", "b", "c", "d") * // -> "d c b a d c b a" * </pre></blockquote> * * <li> <i>Relative indexing</i> is used when the format specifier contains a * {@code '<'} (<code>'\u003c'</code>) flag which causes the argument for * the previous format specifier to be re-used. If there is no previous * argument, then a {@link MissingFormatArgumentException} is thrown. * * <blockquote><pre> * formatter.format("%s %s %<s %<s", "a", "b", "c", "d") * // -> "a b b b" * // "c" and "d" are ignored because they are not referenced * </pre></blockquote> * * <li> <i>Ordinary indexing</i> is used when the format specifier contains * neither an argument index nor a {@code '<'} flag. Each format specifier * which uses ordinary indexing is assigned a sequential implicit index into * argument list which is independent of the indices used by explicit or * relative indexing. * * <blockquote><pre> * formatter.format("%s %s %s %s", "a", "b", "c", "d") * // -> "a b c d" * </pre></blockquote> * * </ul> * * <p> It is possible to have a format string which uses all forms of indexing, * for example: * * <blockquote><pre> * formatter.format("%2$s %s %<s %s", "a", "b", "c", "d") * // -> "b a a b" * // "c" and "d" are ignored because they are not referenced * </pre></blockquote> * * <p> The maximum number of arguments is limited by the maximum dimension of a * Java array as defined by * <cite>The Java Virtual Machine Specification</cite>. * If the argument index does not correspond to an * available argument, then a {@link MissingFormatArgumentException} is thrown. * * <p> If there are more arguments than format specifiers, the extra arguments * are ignored. * * <p> Unless otherwise specified, passing a {@code null} argument to any * method or constructor in this class will cause a {@link * NullPointerException} to be thrown. * * @author Iris Clark * @since 1.5
*/ publicfinalclass Formatter implements Closeable, Flushable { // Caching DecimalFormatSymbols. Non-volatile to avoid thread slamming. privatestatic DecimalFormatSymbols DFS = null; privatestatic DecimalFormatSymbols getDecimalFormatSymbols(Locale locale) { // Capture local copy to avoid thread race.
DecimalFormatSymbols dfs = DFS; if (dfs != null && dfs.getLocale().equals(locale)) { return dfs;
} // Fetch a new local instance of DecimalFormatSymbols. Note that DFS are mutable // and this instance is reserved for Formatter.
dfs = DecimalFormatSymbols.getInstance(locale); // Non-volatile here is acceptable heuristic.
DFS = dfs; return dfs;
}
// Use zero from cached DecimalFormatSymbols. privatestaticchar getZero(Locale locale) { return locale == null ? '0' : getDecimalFormatSymbols(locale).getZeroDigit();
}
// Use decimal separator from cached DecimalFormatSymbols. privatestaticchar getDecimalSeparator(Locale locale) { return locale == null ? '.' : getDecimalFormatSymbols(locale).getDecimalSeparator();
}
// Use grouping separator from cached DecimalFormatSymbols. privatestaticchar getGroupingSeparator(Locale locale) { return locale == null ? ',' : getDecimalFormatSymbols(locale).getGroupingSeparator();
}
/** * Returns a charset object for the given charset name. * @throws NullPointerException is csn is null * @throws UnsupportedEncodingException if the charset is not supported
*/ privatestatic Charset toCharset(String csn) throws UnsupportedEncodingException
{
Objects.requireNonNull(csn, "charsetName"); try { return Charset.forName(csn);
} catch (IllegalCharsetNameException|UnsupportedCharsetException unused) { // UnsupportedEncodingException should be thrown thrownew UnsupportedEncodingException(csn);
}
}
privatestatic Appendable nonNullAppendable(Appendable a) { if (a == null) returnnew StringBuilder();
/** * Constructs a new formatter. * * <p> The destination of the formatted output is a {@link StringBuilder} * which may be retrieved by invoking {@link #out out()} and whose * current content may be converted into a string by invoking {@link * #toString toString()}. The locale used is the {@linkplain * Locale#getDefault(Locale.Category) default locale} for * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java * virtual machine.
*/ public Formatter() { this(Locale.getDefault(Locale.Category.FORMAT), new StringBuilder());
}
/** * Constructs a new formatter with the specified destination. * * <p> The locale used is the {@linkplain * Locale#getDefault(Locale.Category) default locale} for * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java * virtual machine. * * @param a * Destination for the formatted output. If {@code a} is * {@code null} then a {@link StringBuilder} will be created.
*/ public Formatter(Appendable a) { this(Locale.getDefault(Locale.Category.FORMAT), nonNullAppendable(a));
}
/** * Constructs a new formatter with the specified locale. * * <p> The destination of the formatted output is a {@link StringBuilder} * which may be retrieved by invoking {@link #out out()} and whose current * content may be converted into a string by invoking {@link #toString * toString()}. * * @param l * The {@linkplain java.util.Locale locale} to apply during * formatting. If {@code l} is {@code null} then no localization * is applied.
*/ public Formatter(Locale l) { this(l, new StringBuilder());
}
/** * Constructs a new formatter with the specified destination and locale. * * @param a * Destination for the formatted output. If {@code a} is * {@code null} then a {@link StringBuilder} will be created. * * @param l * The {@linkplain java.util.Locale locale} to apply during * formatting. If {@code l} is {@code null} then no localization * is applied.
*/ public Formatter(Appendable a, Locale l) { this(l, nonNullAppendable(a));
}
/** * Constructs a new formatter with the specified file name. * * <p> The charset used is the {@linkplain * java.nio.charset.Charset#defaultCharset() default charset} for this * instance of the Java virtual machine. * * <p> The locale used is the {@linkplain * Locale#getDefault(Locale.Category) default locale} for * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java * virtual machine. * * @param fileName * The name of the file to use as the destination of this * formatter. If the file exists then it will be truncated to * zero size; otherwise, a new file will be created. The output * will be written to the file and is buffered. * * @throws SecurityException * If a security manager is present and {@link * SecurityManager#checkWrite checkWrite(fileName)} denies write * access to the file * * @throws FileNotFoundException * If the given file name does not denote an existing, writable * regular file and a new regular file of that name cannot be * created, or if some other error occurs while opening or * creating the file
*/ public Formatter(String fileName) throws FileNotFoundException { this(Locale.getDefault(Locale.Category.FORMAT), new BufferedWriter(new OutputStreamWriter(new FileOutputStream(fileName))));
}
/** * Constructs a new formatter with the specified file name and charset. * * <p> The locale used is the {@linkplain * Locale#getDefault(Locale.Category) default locale} for * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java * virtual machine. * * @param fileName * The name of the file to use as the destination of this * formatter. If the file exists then it will be truncated to * zero size; otherwise, a new file will be created. The output * will be written to the file and is buffered. * * @param csn * The name of a supported {@linkplain java.nio.charset.Charset * charset} * * @throws FileNotFoundException * If the given file name does not denote an existing, writable * regular file and a new regular file of that name cannot be * created, or if some other error occurs while opening or * creating the file * * @throws SecurityException * If a security manager is present and {@link * SecurityManager#checkWrite checkWrite(fileName)} denies write * access to the file * * @throws UnsupportedEncodingException * If the named charset is not supported
*/ public Formatter(String fileName, String csn) throws FileNotFoundException, UnsupportedEncodingException
{ this(fileName, csn, Locale.getDefault(Locale.Category.FORMAT));
}
/** * Constructs a new formatter with the specified file name, charset, and * locale. * * @param fileName * The name of the file to use as the destination of this * formatter. If the file exists then it will be truncated to * zero size; otherwise, a new file will be created. The output * will be written to the file and is buffered. * * @param csn * The name of a supported {@linkplain java.nio.charset.Charset * charset} * * @param l * The {@linkplain java.util.Locale locale} to apply during * formatting. If {@code l} is {@code null} then no localization * is applied. * * @throws FileNotFoundException * If the given file name does not denote an existing, writable * regular file and a new regular file of that name cannot be * created, or if some other error occurs while opening or * creating the file * * @throws SecurityException * If a security manager is present and {@link * SecurityManager#checkWrite checkWrite(fileName)} denies write * access to the file * * @throws UnsupportedEncodingException * If the named charset is not supported
*/ public Formatter(String fileName, String csn, Locale l) throws FileNotFoundException, UnsupportedEncodingException
{ this(toCharset(csn), l, new File(fileName));
}
/** * Constructs a new formatter with the specified file name, charset, and * locale. * * @param fileName * The name of the file to use as the destination of this * formatter. If the file exists then it will be truncated to * zero size; otherwise, a new file will be created. The output * will be written to the file and is buffered. * * @param charset * A {@linkplain java.nio.charset.Charset charset} * * @param l * The {@linkplain java.util.Locale locale} to apply during * formatting. If {@code l} is {@code null} then no localization * is applied. * * @throws IOException * if an I/O error occurs while opening or creating the file * * @throws SecurityException * If a security manager is present and {@link * SecurityManager#checkWrite checkWrite(fileName)} denies write * access to the file * * @throws NullPointerException * if {@code fileName} or {@code charset} is {@code null}.
*/ public Formatter(String fileName, Charset charset, Locale l) throws IOException { this(Objects.requireNonNull(charset, "charset"), l, new File(fileName));
}
/** * Constructs a new formatter with the specified file. * * <p> The charset used is the {@linkplain * java.nio.charset.Charset#defaultCharset() default charset} for this * instance of the Java virtual machine. * * <p> The locale used is the {@linkplain * Locale#getDefault(Locale.Category) default locale} for * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java * virtual machine. * * @param file * The file to use as the destination of this formatter. If the * file exists then it will be truncated to zero size; otherwise, * a new file will be created. The output will be written to the * file and is buffered. * * @throws SecurityException * If a security manager is present and {@link * SecurityManager#checkWrite checkWrite(file.getPath())} denies * write access to the file * * @throws FileNotFoundException * If the given file object does not denote an existing, writable * regular file and a new regular file of that name cannot be * created, or if some other error occurs while opening or * creating the file
*/ public Formatter(File file) throws FileNotFoundException { this(Locale.getDefault(Locale.Category.FORMAT), new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file))));
}
/** * Constructs a new formatter with the specified file and charset. * * <p> The locale used is the {@linkplain * Locale#getDefault(Locale.Category) default locale} for * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java * virtual machine. * * @param file * The file to use as the destination of this formatter. If the * file exists then it will be truncated to zero size; otherwise, * a new file will be created. The output will be written to the * file and is buffered. * * @param csn * The name of a supported {@linkplain java.nio.charset.Charset * charset} * * @throws FileNotFoundException * If the given file object does not denote an existing, writable * regular file and a new regular file of that name cannot be * created, or if some other error occurs while opening or * creating the file * * @throws SecurityException * If a security manager is present and {@link * SecurityManager#checkWrite checkWrite(file.getPath())} denies * write access to the file * * @throws UnsupportedEncodingException * If the named charset is not supported
*/ public Formatter(File file, String csn) throws FileNotFoundException, UnsupportedEncodingException
{ this(file, csn, Locale.getDefault(Locale.Category.FORMAT));
}
/** * Constructs a new formatter with the specified file, charset, and * locale. * * @param file * The file to use as the destination of this formatter. If the * file exists then it will be truncated to zero size; otherwise, * a new file will be created. The output will be written to the * file and is buffered. * * @param csn * The name of a supported {@linkplain java.nio.charset.Charset * charset} * * @param l * The {@linkplain java.util.Locale locale} to apply during * formatting. If {@code l} is {@code null} then no localization * is applied. * * @throws FileNotFoundException * If the given file object does not denote an existing, writable * regular file and a new regular file of that name cannot be * created, or if some other error occurs while opening or * creating the file * * @throws SecurityException * If a security manager is present and {@link * SecurityManager#checkWrite checkWrite(file.getPath())} denies * write access to the file * * @throws UnsupportedEncodingException * If the named charset is not supported
*/ public Formatter(File file, String csn, Locale l) throws FileNotFoundException, UnsupportedEncodingException
{ this(toCharset(csn), l, file);
}
/** * Constructs a new formatter with the specified file, charset, and * locale. * * @param file * The file to use as the destination of this formatter. If the * file exists then it will be truncated to zero size; otherwise, * a new file will be created. The output will be written to the * file and is buffered. * * @param charset * A {@linkplain java.nio.charset.Charset charset} * * @param l * The {@linkplain java.util.Locale locale} to apply during * formatting. If {@code l} is {@code null} then no localization * is applied. * * @throws IOException * if an I/O error occurs while opening or creating the file * * @throws SecurityException * If a security manager is present and {@link * SecurityManager#checkWrite checkWrite(file.getPath())} denies * write access to the file * * @throws NullPointerException * if {@code file} or {@code charset} is {@code null}.
*/ public Formatter(File file, Charset charset, Locale l) throws IOException { this(Objects.requireNonNull(charset, "charset"), l, file);
}
/** * Constructs a new formatter with the specified print stream. * * <p> The locale used is the {@linkplain * Locale#getDefault(Locale.Category) default locale} for * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java * virtual machine. * * <p> Characters are written to the given {@link java.io.PrintStream * PrintStream} object and are therefore encoded using that object's * charset. * * @param ps * The stream to use as the destination of this formatter.
*/ public Formatter(PrintStream ps) { this(Locale.getDefault(Locale.Category.FORMAT),
(Appendable)Objects.requireNonNull(ps));
}
/** * Constructs a new formatter with the specified output stream. * * <p> The charset used is the {@linkplain * java.nio.charset.Charset#defaultCharset() default charset} for this * instance of the Java virtual machine. * * <p> The locale used is the {@linkplain * Locale#getDefault(Locale.Category) default locale} for * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java * virtual machine. * * @param os * The output stream to use as the destination of this formatter. * The output will be buffered.
*/ public Formatter(OutputStream os) { this(Locale.getDefault(Locale.Category.FORMAT), new BufferedWriter(new OutputStreamWriter(os)));
}
/** * Constructs a new formatter with the specified output stream and * charset. * * <p> The locale used is the {@linkplain * Locale#getDefault(Locale.Category) default locale} for * {@linkplain Locale.Category#FORMAT formatting} for this instance of the Java * virtual machine. * * @param os * The output stream to use as the destination of this formatter. * The output will be buffered. * * @param csn * The name of a supported {@linkplain java.nio.charset.Charset * charset} * * @throws UnsupportedEncodingException * If the named charset is not supported
*/ public Formatter(OutputStream os, String csn) throws UnsupportedEncodingException
{ this(os, csn, Locale.getDefault(Locale.Category.FORMAT));
}
/** * Constructs a new formatter with the specified output stream, charset, * and locale. * * @param os * The output stream to use as the destination of this formatter. * The output will be buffered. * * @param csn * The name of a supported {@linkplain java.nio.charset.Charset * charset} * * @param l * The {@linkplain java.util.Locale locale} to apply during * formatting. If {@code l} is {@code null} then no localization * is applied. * * @throws UnsupportedEncodingException * If the named charset is not supported
*/ public Formatter(OutputStream os, String csn, Locale l) throws UnsupportedEncodingException
{ this(l, new BufferedWriter(new OutputStreamWriter(os, csn)));
}
/** * Constructs a new formatter with the specified output stream, charset, * and locale. * * @param os * The output stream to use as the destination of this formatter. * The output will be buffered. * * @param charset * A {@linkplain java.nio.charset.Charset charset} * * @param l * The {@linkplain java.util.Locale locale} to apply during * formatting. If {@code l} is {@code null} then no localization * is applied. * * @throws NullPointerException * if {@code os} or {@code charset} is {@code null}.
*/ public Formatter(OutputStream os, Charset charset, Locale l) { this(l, new BufferedWriter(new OutputStreamWriter(os, charset)));
}
/** * Returns the locale set by the construction of this formatter. * * <p> The {@link #format(java.util.Locale,String,Object...) format} method * for this object which has a locale argument does not change this value. * * @return {@code null} if no localization is applied, otherwise a * locale * * @throws FormatterClosedException * If this formatter has been closed by invoking its {@link * #close()} method
*/ public Locale locale() {
ensureOpen(); return l;
}
/** * Returns the destination for the output. * * @return The destination for the output * * @throws FormatterClosedException * If this formatter has been closed by invoking its {@link * #close()} method
*/ public Appendable out() {
ensureOpen(); return a;
}
/** * Returns the result of invoking {@code toString()} on the destination * for the output. For example, the following code formats text into a * {@link StringBuilder} then retrieves the resultant string: * * <blockquote><pre> * Formatter f = new Formatter(); * f.format("Last reboot at %tc", lastRebootDate); * String s = f.toString(); * // -> s == "Last reboot at Sat Jan 01 00:00:00 PST 2000" * </pre></blockquote> * * <p> An invocation of this method behaves in exactly the same way as the * invocation * * <pre> * out().toString() </pre> * * <p> Depending on the specification of {@code toString} for the {@link * Appendable}, the returned string may or may not contain the characters * written to the destination. For instance, buffers typically return * their contents in {@code toString()}, but streams cannot since the * data is discarded. * * @return The result of invoking {@code toString()} on the destination * for the output * * @throws FormatterClosedException * If this formatter has been closed by invoking its {@link * #close()} method
*/ public String toString() {
ensureOpen(); return a.toString();
}
/** * Flushes this formatter. If the destination implements the {@link * java.io.Flushable} interface, its {@code flush} method will be invoked. * * <p> Flushing a formatter writes any buffered output in the destination * to the underlying stream. * * @throws FormatterClosedException * If this formatter has been closed by invoking its {@link * #close()} method
*/ publicvoid flush() {
ensureOpen(); if (a instanceof Flushable) { try {
((Flushable)a).flush();
} catch (IOException ioe) {
lastException = ioe;
}
}
}
/** * Closes this formatter. If the destination implements the {@link * java.io.Closeable} interface, its {@code close} method will be invoked. * * <p> Closing a formatter allows it to release resources it may be holding * (such as open files). If the formatter is already closed, then invoking * this method has no effect. * * <p> Attempting to invoke any methods except {@link #ioException()} in * this formatter after it has been closed will result in a {@link * FormatterClosedException}.
*/ publicvoid close() { if (a == null) return; try { if (a instanceof Closeable)
((Closeable)a).close();
} catch (IOException ioe) {
lastException = ioe;
} finally {
a = null;
}
}
privatevoid ensureOpen() { if (a == null) thrownew FormatterClosedException();
}
/** * Returns the {@code IOException} last thrown by this formatter's {@link * Appendable}. * * <p> If the destination's {@code append()} method never throws * {@code IOException}, then this method will always return {@code null}. * * @return The last exception thrown by the Appendable or {@code null} if * no such exception exists.
*/ public IOException ioException() { return lastException;
}
/** * Writes a formatted string to this object's destination using the * specified format string and arguments. The locale used is the one * defined during the construction of this formatter. * * @param format * A format string as described in <a href="#syntax">Format string * syntax</a>. * * @param args * Arguments referenced by the format specifiers in the format * string. If there are more arguments than format specifiers, the * extra arguments are ignored. The maximum number of arguments is * limited by the maximum dimension of a Java array as defined by * <cite>The Java Virtual Machine Specification</cite>. * * @throws IllegalFormatException * If a format string contains an illegal syntax, a format * specifier that is incompatible with the given arguments, * insufficient arguments given the format string, or other * illegal conditions. For specification of all possible * formatting errors, see the <a href="#detail">Details</a> * section of the formatter class specification. * * @throws FormatterClosedException * If this formatter has been closed by invoking its {@link * #close()} method * * @return This formatter
*/ public Formatter format(String format, Object ... args) { return format(l, format, args);
}
/** * Writes a formatted string to this object's destination using the * specified locale, format string, and arguments. * * @param l * The {@linkplain java.util.Locale locale} to apply during * formatting. If {@code l} is {@code null} then no localization * is applied. This does not change this object's locale that was * set during construction. * * @param format * A format string as described in <a href="#syntax">Format string * syntax</a> * * @param args * Arguments referenced by the format specifiers in the format * string. If there are more arguments than format specifiers, the * extra arguments are ignored. The maximum number of arguments is * limited by the maximum dimension of a Java array as defined by * <cite>The Java Virtual Machine Specification</cite>. * * @throws IllegalFormatException * If a format string contains an illegal syntax, a format * specifier that is incompatible with the given arguments, * insufficient arguments given the format string, or other * illegal conditions. For specification of all possible * formatting errors, see the <a href="#detail">Details</a> * section of the formatter class specification. * * @throws FormatterClosedException * If this formatter has been closed by invoking its {@link * #close()} method * * @return This formatter
*/ public Formatter format(Locale l, String format, Object ... args) {
ensureOpen();
// index of last argument referenced int last = -1; // last ordinary index int lasto = -1;
List<FormatString> fsa = parse(format); for (int i = 0; i < fsa.size(); i++) { var fs = fsa.get(i); int index = fs.index(); try { switch (index) { case -2 -> // fixed string, "%n", or "%%"
fs.print(this, null, l); case -1 -> { // relative index if (last < 0 || (args != null && last > args.length - 1)) thrownew MissingFormatArgumentException(fs.toString());
fs.print(this, (args == null ? null : args[last]), l);
} case 0 -> { // ordinary index
lasto++;
last = lasto; if (args != null && lasto > args.length - 1) thrownew MissingFormatArgumentException(fs.toString());
fs.print(this, (args == null ? null : args[lasto]), l);
} default -> { // explicit index
last = index - 1; if (args != null && last > args.length - 1) thrownew MissingFormatArgumentException(fs.toString());
fs.print(this, (args == null ? null : args[last]), l);
}
}
} catch (IOException x) {
lastException = x;
}
} returnthis;
}
/** * Finds format specifiers in the format string.
*/ private List<FormatString> parse(String s) {
ArrayList<FormatString> al = new ArrayList<>(); int i = 0; int max = s.length();
Matcher m = null; // create if needed while (i < max) { int n = s.indexOf('%', i); if (n < 0) { // No more format specifiers, but since // i < max there's some trailing text
al.add(new FixedString(s, i, max)); break;
} if (i != n) { // Previous characters were fixed text
al.add(new FixedString(s, i, n));
}
i = n + 1; if (i >= max) { // Trailing % thrownew UnknownFormatConversionException("%");
} char c = s.charAt(i); if (Conversion.isValid(c)) {
al.add(new FormatSpecifier(c));
i++;
} else { if (m == null) {
m = fsPattern.matcher(s);
} // We have already parsed a '%' at n, so we either have a // match or the specifier at n is invalid if (m.find(n) && m.start() == n) {
al.add(new FormatSpecifier(s, m));
i = m.end();
} else { thrownew UnknownFormatConversionException(String.valueOf(c));
}
}
} return al;
}
privatevoid index(String s, int start, int end) { if (start >= 0) { try { // skip the trailing '$'
index = Integer.parseInt(s, start, end - 1, 10); if (index <= 0) { thrownew IllegalFormatArgumentIndexException(index);
}
} catch (NumberFormatException x) { thrownew IllegalFormatArgumentIndexException(Integer.MIN_VALUE);
}
}
}
publicint index() { return index;
}
privatevoid flags(String s, int start, int end) {
flags = Flags.parse(s, start, end); if (Flags.contains(flags, Flags.PREVIOUS))
index = -1;
}
privatevoid width(String s, int start, int end) { if (start >= 0) { try {
width = Integer.parseInt(s, start, end, 10); if (width < 0) thrownew IllegalFormatWidthException(width);
} catch (NumberFormatException x) { thrownew IllegalFormatWidthException(Integer.MIN_VALUE);
}
}
}
privatevoid precision(String s, int start, int end) { if (start >= 0) { try { // skip the leading '.'
precision = Integer.parseInt(s, start + 1, end, 10); if (precision < 0) thrownew IllegalFormatPrecisionException(precision);
} catch (NumberFormatException x) { thrownew IllegalFormatPrecisionException(Integer.MIN_VALUE);
}
}
}
privatevoid conversion(char conv) {
c = conv; if (!dt) { if (!Conversion.isValid(c)) { thrownew UnknownFormatConversionException(String.valueOf(c));
} if (Character.isUpperCase(c)) {
flags = Flags.add(flags, Flags.UPPERCASE);
c = Character.toLowerCase(c);
} if (Conversion.isText(c)) {
index = -2;
}
}
}
FormatSpecifier(char conv) {
c = conv; if (Character.isUpperCase(conv)) {
flags = Flags.UPPERCASE;
c = Character.toLowerCase(conv);
} if (Conversion.isText(conv)) {
index = -2;
}
}
// Instead of Calendar.setLenient(true), perhaps we should // wrap the IllegalArgumentException that might be thrown? if (arg instanceofLong) { // Note that the following method uses an instance of the // default time zone (TimeZone.getDefaultRef().
cal = Calendar.getInstance(l == null ? Locale.US : l);
cal.setTimeInMillis((Long)arg);
} elseif (arg instanceof Date) { // Note that the following method uses an instance of the // default time zone (TimeZone.getDefaultRef().
cal = Calendar.getInstance(l == null ? Locale.US : l);
cal.setTime((Date)arg);
} elseif (arg instanceof Calendar) {
cal = (Calendar) ((Calendar) arg).clone();
cal.setLenient(true);
} elseif (arg instanceof TemporalAccessor) {
print(fmt, (TemporalAccessor) arg, c, l); return;
} else {
failConversion(c, arg);
} // Use the provided locale so that invocations of // localizedMagnitude() use optimizations for null.
print(fmt, cal, c, l);
}
privatevoid printCharacter(Formatter fmt, Object arg, Locale l) throws IOException { if (arg == null) {
print(fmt, "null", l); return;
}
String s = null; if (arg instanceof Character) {
s = ((Character)arg).toString();
} elseif (arg instanceofByte) { byte i = (Byte) arg; if (Character.isValidCodePoint(i))
s = new String(Character.toChars(i)); else thrownew IllegalFormatCodePointException(i);
} elseif (arg instanceofShort) { short i = (Short) arg; if (Character.isValidCodePoint(i))
s = new String(Character.toChars(i)); else thrownew IllegalFormatCodePointException(i);
} elseif (arg instanceof Integer) { int i = (Integer) arg; if (Character.isValidCodePoint(i))
s = new String(Character.toChars(i)); else thrownew IllegalFormatCodePointException(i);
} else {
failConversion(c, arg);
}
print(fmt, s, l);
}
privatevoid printString(Formatter fmt, Object arg, Locale l) throws IOException { if (arg instanceof Formattable) { if (fmt.locale() != l)
fmt = new Formatter(fmt.out(), l);
((Formattable)arg).formatTo(fmt, flags, width, precision);
} else { if (Flags.contains(flags, Flags.ALTERNATE))
failMismatch(Flags.ALTERNATE, 's'); if (arg == null)
print(fmt, "null", l); else
print(fmt, arg.toString(), l);
}
}
StringBuilder mant = new StringBuilder().append(fd.getMantissa());
addZeros(mant, prec);
// If the precision is zero and the '#' flag is set, add the // requested decimal point. if (Flags.contains(flags, Flags.ALTERNATE) && (prec == 0)) {
mant.append('.');
}
StringBuilder mant = new StringBuilder().append(fd.getMantissa());
addZeros(mant, prec);
// If the precision is zero and the '#' flag is set, add the // requested decimal point. if (Flags.contains(flags, Flags.ALTERNATE) && (prec == 0))
mant.append('.');
addZeros(mant, prec); // If the precision is zero and the '#' flag is set, add the // requested decimal point. if (Flags.contains(flags, Flags.ALTERNATE) && (prec == 0)) {
mant.append('.');
}
// Add zeros to the requested precision. privatevoid addZeros(StringBuilder sb, int prec) { // Look for the dot. If we don't find one, the we'll need to add // it before we add the zeros. int len = sb.length(); int i; for (i = 0; i < len; i++) { if (sb.charAt(i) == '.') { break;
}
} boolean needDot = false; if (i == len) {
needDot = true;
}
// Determine existing precision. int outPrec = len - i - (needDot ? 0 : 1); assert (outPrec <= prec); if (outPrec == prec) { return;
}
// Add dot if previously determined to be necessary. if (needDot) {
sb.append('.');
}
// If this is subnormal input so normalize (could be faster to // do as integer operation). if (subnormal) { double scaleUp = Math.scalb(1.0, 54);
d *= scaleUp; // Calculate the exponent. This is not just exponent + 54 // since the former is not the normalized exponent.
exponent = Math.getExponent(d); assert exponent >= Double.MIN_EXPONENT &&
exponent <= Double.MAX_EXPONENT: exponent;
}
int precision = 1 + prec*4; int shiftDistance
= DoubleConsts.SIGNIFICAND_WIDTH - precision; assert(shiftDistance >= 1 && shiftDistance < DoubleConsts.SIGNIFICAND_WIDTH);
long doppel = Double.doubleToLongBits(d); // Deterime the number of bits to keep. long newSignif
= (doppel & (DoubleConsts.EXP_BIT_MASK
| DoubleConsts.SIGNIF_BIT_MASK))
>> shiftDistance; // Bits to round away. long roundingBits = doppel & ~(~0L << shiftDistance);
// To decide how to round, look at the low-order bit of the // working significand, the highest order discarded bit (the // round bit) and whether any of the lower order discarded bits // are nonzero (the sticky bit).
long signBit = doppel & DoubleConsts.SIGN_BIT_MASK;
newSignif = signBit | (newSignif << shiftDistance); double result = Double.longBitsToDouble(newSignif);
if (Double.isInfinite(result) ) { // Infinite result generated by rounding return"1.0p1024";
} else {
String res = Double.toHexString(result).substring(2); if (!subnormal) return res; else { // Create a normalized subnormal string. int idx = res.indexOf('p'); if (idx == -1) { // No 'p' character in hex string. assertfalse; returnnull;
} else { // Get exponent and append at the end.
String exp = res.substring(idx + 1); int iexp = Integer.parseInt(exp) -54; return res.substring(0, idx) + "p"
+ Integer.toString(iexp);
}
}
}
}
}
privatevoid print(Formatter fmt, BigDecimal value, Locale l) throws IOException { if (c == Conversion.HEXADECIMAL_FLOAT)
failConversion(c, value);
StringBuilder sb = new StringBuilder(); boolean neg = value.signum() == -1;
BigDecimal v = value.abs(); // leading sign indicator
leadingSign(sb, neg);
// the value
print(fmt, sb, v, l, flags, c, precision, neg);
// trailing sign indicator
trailingSign(sb, neg);
// justify based on width
appendJustified(fmt.a, sb);
}
// value > 0 privatevoid print(Formatter fmt, StringBuilder sb, BigDecimal value, Locale l, int flags, char c, int precision, boolean neg) throws IOException
{ if (c == Conversion.SCIENTIFIC) { // Create a new BigDecimal with the desired precision. int prec = (precision == -1 ? 6 : precision); int scale = value.scale(); int origPrec = value.precision(); int nzeros = 0; int compPrec;
MathContext mc = new MathContext(compPrec);
BigDecimal v
= new BigDecimal(value.unscaledValue(), scale, mc);
BigDecimalLayout bdl
= new BigDecimalLayout(v.unscaledValue(), v.scale(),
BigDecimalLayoutForm.SCIENTIFIC);
StringBuilder mant = bdl.mantissa();
// Add a decimal point if necessary. The mantissa may not // contain a decimal point if the scale is zero (the internal // representation has no fractional part) or the original // precision is one. Append a decimal point if '#' is set or if // we require zero padding to get to the requested precision. if ((origPrec == 1 || !bdl.hasDot())
&& (nzeros > 0 || (Flags.contains(flags, Flags.ALTERNATE)))) {
mant.append('.');
}
// Add trailing zeros in the case precision is greater than // the number of available digits after the decimal separator.
trailingZeros(mant, nzeros);
sb.append(localizedMagnitude(fmt, null, exp, 1, adaptedFlags, -1, l));
} elseif (c == Conversion.DECIMAL_FLOAT) { // Create a new BigDecimal with the desired precision. int prec = (precision == -1 ? 6 : precision); int scale = value.scale();
if (scale > prec) { // more "scale" digits than the requested "precision" int compPrec = value.precision(); if (compPrec <= scale) { // case of 0.xxxxxx
value = value.setScale(prec, RoundingMode.HALF_UP);
} else {
compPrec -= (scale - prec);
value = new BigDecimal(value.unscaledValue(),
scale, new MathContext(compPrec));
}
}
BigDecimalLayout bdl = new BigDecimalLayout(
value.unscaledValue(),
value.scale(),
BigDecimalLayoutForm.DECIMAL_FLOAT);
// Add a decimal point if necessary. The mantissa may not // contain a decimal point if the scale is zero (the internal // representation has no fractional part). Append a decimal // point if '#' is set or we require zero padding to get to the // requested precision. if (bdl.scale() == 0 && (Flags.contains(flags, Flags.ALTERNATE)
|| nzeros > 0)) {
mant.append('.');
}
// Add trailing zeros if the precision is greater than the // number of available digits after the decimal separator.
trailingZeros(mant, nzeros);
public BigDecimalLayout(BigInteger intVal, int scale, BigDecimalLayoutForm form) {
layout(intVal, scale, form);
}
publicboolean hasDot() { return dot;
}
publicint scale() { return scale;
}
public StringBuilder mantissa() { return mant;
}
// The exponent will be formatted as a sign ('+' or '-') followed // by the exponent zero-padded to include at least two digits. public StringBuilder exponent() { return exp;
}
// Construct a buffer, with sufficient capacity for all cases. // If E-notation is needed, length will be: +1 if negative, +1 // if '.' needed, +2 for "E+", + up to 10 for adjusted // exponent. Otherwise it could have +1 if negative, plus // leading "0.00000" int len = coeff.length();
mant = new StringBuilder(len + 14);
if (scale == 0) { if (len > 1) {
mant.append(coeff.charAt(0)); if (form == BigDecimalLayoutForm.SCIENTIFIC) {
mant.append('.');
dot = true;
mant.append(coeff, 1, len);
exp = new StringBuilder("+"); if (len < 10) {
exp.append('0').append(len - 1);
} else {
exp.append(len - 1);
}
} else {
mant.append(coeff, 1, len);
}
} else {
mant.append(coeff); if (form == BigDecimalLayoutForm.SCIENTIFIC) {
exp = new StringBuilder("+00");
}
}
} elseif (form == BigDecimalLayoutForm.DECIMAL_FLOAT) { // count of padding zeros
if (scale >= len) { // 0.xxx form
mant.append("0.");
dot = true;
trailingZeros(mant, scale - len);
mant.append(coeff);
} else { if (scale > 0) { // xx.xx form int pad = len - scale;
mant.append(coeff, 0, pad);
mant.append('.');
dot = true;
mant.append(coeff, pad, len);
} else { // scale < 0 // xx form
mant.append(coeff, 0, len); if (intVal.signum() != 0) {
trailingZeros(mant, -scale);
} this.scale = 0;
}
}
} else { // x.xxx form
mant.append(coeff.charAt(0)); if (len > 1) {
mant.append('.');
dot = true;
mant.append(coeff, 1, len);
}
exp = new StringBuilder(); long adjusted = -(long) scale + (len - 1); if (adjusted != 0) { long abs = Math.abs(adjusted); // require sign
exp.append(adjusted < 0 ? '-' : '+'); if (abs < 10) {
exp.append('0');
}
exp.append(abs);
} else {
exp.append("+00");
}
}
}
}
privateint adjustWidth(int width, int flags, boolean neg) { int newW = width; if (newW != -1 && neg && Flags.contains(flags, Flags.PARENTHESES))
newW--; return newW;
}
// Add trailing zeros privatevoid trailingZeros(StringBuilder sb, int nzeros) { for (int i = 0; i < nzeros; i++) {
sb.append('0');
}
}
// Use DecimalFormat constructor to obtain the instance, // in case NumberFormat.getNumberInstance(l) // returns instance other than DecimalFormat
LocaleProviderAdapter adapter = LocaleProviderAdapter
.getAdapter(NumberFormatProvider.class, l); if (!(adapter instanceof ResourceBundleBasedAdapter)) {
adapter = LocaleProviderAdapter.getResourceBundleBased();
}
String[] all = adapter.getLocaleResources(l)
.getNumberPatterns();
df = new DecimalFormat(all[0], getDecimalFormatSymbols(l));
}
grpSize = df.getGroupingSize(); // Some locales do not use grouping (the number // pattern for these locales does not contain group, e.g. // ("#0.###")), but specify a grouping separator. // To avoid unnecessary identification of the position of // grouping separator, reset its value with null character if (!df.isGroupingUsed() || grpSize == 0) {
grpSep = '\0';
}
}
}
// localize the digits inserting group separators as necessary for (int j = offset; j < len; j++) { if (j == dot) {
sb.append(decSep); // no more group separators after the decimal separator
grpSep = '\0'; continue;
}
// apply zero padding if (width != -1 && Flags.contains(f, Flags.ZERO_PAD)) { for (int k = sb.length(); k < width; k++) {
sb.insert(begin, zero);
}
}
return sb;
}
// Specialized localization of exponents, where the source value can only // contain characters '0' through '9', starting at index offset, and no // group separators is added for any locale. privatevoid localizedMagnitudeExp(Formatter fmt, StringBuilder sb, char[] value, finalint offset, Locale l) { char zero = getZero(l);
int len = value.length; for (int j = offset; j < len; j++) { char c = value[j];
sb.append((char) ((c - '0') + zero));
}
}
}
publicstaticint parse(String s, int start, int end) { int f = 0; for (int i = start; i < end; i++) { char c = s.charAt(i); int v = parse(c); if (contains(f, v)) thrownew DuplicateFormatFlagsException(toString(v));
f = add(f, v);
} return f;
}
// parse those flags which may be provided by users privatestaticint parse(char c) { returnswitch (c) { case'-' -> LEFT_JUSTIFY; case'#' -> ALTERNATE; case'+' -> PLUS; case' ' -> LEADING_SPACE; case'0' -> ZERO_PAD; case',' -> GROUP; case'(' -> PARENTHESES; case'<' -> PREVIOUS; default -> thrownew UnknownFormatFlagsException(String.valueOf(c));
};
}
// Returns a string representation of the current {@code Flags}. publicstatic String toString(int f) {
StringBuilder sb = new StringBuilder(); if (contains(f, LEFT_JUSTIFY)) sb.append('-'); if (contains(f, UPPERCASE)) sb.append('^'); if (contains(f, ALTERNATE)) sb.append('#'); if (contains(f, PLUS)) sb.append('+'); if (contains(f, LEADING_SPACE)) sb.append(' '); if (contains(f, ZERO_PAD)) sb.append('0'); if (contains(f, GROUP)) sb.append(','); if (contains(f, PARENTHESES)) sb.append('('); if (contains(f, PREVIOUS)) sb.append('<'); return sb.toString();
}
}
// Returns true iff the Conversion is applicable to all objects. staticboolean isGeneral(char c) { returnswitch (c) { caseBOOLEAN,
BOOLEAN_UPPER,
STRING,
STRING_UPPER,
HASHCODE,
HASHCODE_UPPER -> true; default -> false;
};
}
// Returns true iff the Conversion is applicable to character. staticboolean isCharacter(char c) { returnswitch (c) { case CHARACTER,
CHARACTER_UPPER -> true; default -> false;
};
}
// Returns true iff the Conversion is an integer type. staticboolean isInteger(char c) { returnswitch (c) { case DECIMAL_INTEGER,
OCTAL_INTEGER,
HEXADECIMAL_INTEGER,
HEXADECIMAL_INTEGER_UPPER -> true; default -> false;
};
}
// Returns true iff the Conversion is a floating-point type. staticboolean isFloat(char c) { returnswitch (c) { case SCIENTIFIC,
SCIENTIFIC_UPPER,
GENERAL,
GENERAL_UPPER,
DECIMAL_FLOAT,
HEXADECIMAL_FLOAT,
HEXADECIMAL_FLOAT_UPPER -> true; default -> false;
};
}
// Returns true iff the Conversion does not require an argument staticboolean isText(char c) { returnswitch (c) { case LINE_SEPARATOR, PERCENT_SIGN -> true; default -> false;
};
}
}
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