/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jasper.runtime;
import java.io.IOException;
import java.io.Writer;
import jakarta.servlet.ServletResponse;
import jakarta.servlet.jsp.JspWriter;
import org.apache.jasper.Constants;
import org.apache.jasper.compiler.Localizer;
/**
* Write text to a character-output stream, buffering characters so as
* to provide for the efficient writing of single characters, arrays,
* and strings.
*
* Provide support for discarding for the output that has been
* buffered.
*
* This needs revisiting when the buffering problems in the JSP spec
* are fixed -akv
*
* @author Anil K. Vijendran
*/
public class JspWriterImpl
extends JspWriter {
private Writer out;
private ServletResponse response;
private char cb[];
private int nextChar;
private boolean flushed =
false;
private boolean closed =
false;
public JspWriterImpl() {
super( Constants.DEFAULT_BUFFER_SIZE,
true );
}
/**
* Create a new buffered character-output stream that uses an output
* buffer of the given size.
*
* @param response A Servlet Response
* @param sz Output-buffer size, a positive integer
* @param autoFlush <code>true</code> to automatically flush on buffer
* full, <code>false</code> to throw an overflow exception in that case
* @exception IllegalArgumentException If sz is <= 0
*/
public JspWriterImpl(ServletResponse response,
int sz,
boolean autoFlush) {
super(sz, autoFlush);
if (sz < 0) {
throw new IllegalArgumentException(Localizer.getMessage(
"jsp.error.negativeBufferSize"));
}
this.response = response;
cb = sz == 0 ?
null :
new char[sz];
nextChar = 0;
}
void init( ServletResponse response,
int sz,
boolean autoFlush ) {
this.response= response;
if( sz > 0 && ( cb ==
null || sz > cb.length ) ) {
cb=
new char[sz];
}
nextChar = 0;
this.autoFlush=autoFlush;
this.bufferSize=sz;
}
/**
* Package-level access
*/
void recycle() {
flushed =
false;
closed =
false;
out =
null;
nextChar = 0;
response =
null;
}
/**
* Flush the output buffer to the underlying character stream, without
* flushing the stream itself. This method is non-private only so that it
* may be invoked by PrintStream.
* @throws IOException Error writing buffered data
*/
protected final void flushBuffer()
throws IOException {
if (bufferSize == 0) {
return;
}
flushed =
true;
ensureOpen();
if (nextChar == 0) {
return;
}
initOut();
out.write(cb, 0, nextChar);
nextChar = 0;
}
private void initOut()
throws IOException {
if (out ==
null) {
out = response.getWriter();
}
}
/**
* Discard the output buffer.
*/
@Override
public final void clear()
throws IOException {
if ((bufferSize == 0) && (out !=
null)) {
// clear() is illegal after any unbuffered output (JSP.5.5)
throw new IllegalStateException(
Localizer.getMessage(
"jsp.error.ise_on_clear"));
}
if (flushed) {
throw new IOException(
Localizer.getMessage(
"jsp.error.attempt_to_clear_flushed_buffer"));
}
ensureOpen();
nextChar = 0;
}
@Override
public void clearBuffer()
throws IOException {
if (bufferSize == 0) {
throw new IllegalStateException(
Localizer.getMessage(
"jsp.error.ise_on_clear"));
}
ensureOpen();
nextChar = 0;
}
private void bufferOverflow()
throws IOException {
throw new IOException(Localizer.getMessage(
"jsp.error.overflow"));
}
/**
* Flush the stream.
*
*/
@Override
public void flush()
throws IOException {
flushBuffer();
if (out !=
null) {
out.flush();
}
}
/**
* Close the stream.
*
*/
@Override
public void close()
throws IOException {
if (response ==
null || closed) {
// multiple calls to close is OK
return;
}
flush();
if (out !=
null) {
out.close();
}
out =
null;
closed =
true;
}
/**
* @return the number of bytes unused in the buffer
*/
@Override
public int getRemaining() {
return bufferSize - nextChar;
}
/** check to make sure that the stream has not been closed */
private void ensureOpen()
throws IOException {
if (response ==
null || closed) {
throw new IOException(Localizer.getMessage(
"jsp.error.stream.closed"));
}
}
/**
* Write a single character.
*/
@Override
public void write(
int c)
throws IOException {
ensureOpen();
if (bufferSize == 0) {
initOut();
out.write(c);
}
else {
if (nextChar >= bufferSize) {
if (autoFlush) {
flushBuffer();
}
else {
bufferOverflow();
}
}
cb[nextChar++] = (
char) c;
}
}
/**
* Our own little min method, to avoid loading java.lang.Math if we've run
* out of file descriptors and we're trying to print a stack trace.
*/
private static int min(
int a,
int b) {
if (a < b) {
return a;
}
return b;
}
/**
* Write a portion of an array of characters.
*
* <p> Ordinarily this method stores characters from the given array into
* this stream's buffer, flushing the buffer to the underlying stream as
* needed. If the requested length is at least as large as the buffer,
* however, then this method will flush the buffer and write the characters
* directly to the underlying stream. Thus redundant
* <code>DiscardableBufferedWriter</code>s will not copy data unnecessarily.
*
* @param cbuf A character array
* @param off Offset from which to start reading characters
* @param len Number of characters to write
*/
@Override
public void write(
char cbuf[],
int off,
int len)
throws IOException
{
ensureOpen();
if (bufferSize == 0) {
initOut();
out.write(cbuf, off, len);
return;
}
if ((off < 0) || (off > cbuf.length) || (len < 0) ||
((off + len) > cbuf.length) || ((off + len) < 0)) {
throw new IndexOutOfBoundsException();
}
else if (len == 0) {
return;
}
if (len >= bufferSize) {
/* If the request length exceeds the size of the output buffer,
flush the buffer and then write the data directly. In this
way buffered streams will cascade harmlessly. */
if (autoFlush) {
flushBuffer();
}
else {
bufferOverflow();
}
initOut();
out.write(cbuf, off, len);
return;
}
int b = off, t = off + len;
while (b < t) {
int d = min(bufferSize - nextChar, t - b);
System.arraycopy(cbuf, b, cb, nextChar, d);
b += d;
nextChar += d;
if (nextChar >= bufferSize) {
if (autoFlush) {
flushBuffer();
}
else {
bufferOverflow();
}
}
}
}
/**
* Write an array of characters. This method cannot be inherited from the
* Writer class because it must suppress I/O exceptions.
*/
@Override
public void write(
char buf[])
throws IOException {
write(buf, 0, buf.length);
}
/**
* Write a portion of a String.
*
* @param s String to be written
* @param off Offset from which to start reading characters
* @param len Number of characters to be written
*/
@Override
public void write(String s,
int off,
int len)
throws IOException {
ensureOpen();
if (bufferSize == 0) {
initOut();
out.write(s, off, len);
return;
}
int b = off, t = off + len;
while (b < t) {
int d = min(bufferSize - nextChar, t - b);
s.getChars(b, b + d, cb, nextChar);
b += d;
nextChar += d;
if (nextChar >= bufferSize) {
if (autoFlush) {
flushBuffer();
}
else {
bufferOverflow();
}
}
}
}
/**
* Write a line separator. The line separator string is defined by the
* system property <code>line.separator</code>, and is not necessarily a
* single newline ('\n') character.
*
* @exception IOException If an I/O error occurs
*/
@Override
public void newLine()
throws IOException {
write(System.lineSeparator());
}
/* Methods that do not terminate lines */
/**
* Print a boolean value. The string produced by <code>{@link
* String#valueOf(boolean)}</code> is translated into bytes
* according to the platform's default character encoding, and these bytes
* are written in exactly the manner of the <code>{@link
* #write(int)}</code> method.
*
* @param b The <code>boolean</code> to be printed
*/
@Override
public void print(
boolean b)
throws IOException {
write(b ?
"true" :
"false");
}
/**
* Print a character. The character is translated into one or more bytes
* according to the platform's default character encoding, and these bytes
* are written in exactly the manner of the <code>{@link
* #write(int)}</code> method.
*
* @param c The <code>char</code> to be printed
*/
@Override
public void print(
char c)
throws IOException {
write(String.valueOf(c));
}
/**
* Print an integer. The string produced by <code>{@link
* String#valueOf(int)}</code> is translated into bytes according
* to the platform's default character encoding, and these bytes are
* written in exactly the manner of the <code>{@link #write(int)}</code>
* method.
*
* @param i The <code>int</code> to be printed
*/
@Override
public void print(
int i)
throws IOException {
write(String.valueOf(i));
}
/**
* Print a long integer. The string produced by <code>{@link
* String#valueOf(long)}</code> is translated into bytes
* according to the platform's default character encoding, and these bytes
* are written in exactly the manner of the <code>{@link #write(int)}</code>
* method.
*
* @param l The <code>long</code> to be printed
*/
@Override
public void print(
long l)
throws IOException {
write(String.valueOf(l));
}
/**
* Print a floating-point number. The string produced by <code>{@link
* String#valueOf(float)}</code> is translated into bytes
* according to the platform's default character encoding, and these bytes
* are written in exactly the manner of the <code>{@link #write(int)}</code>
* method.
*
* @param f The <code>float</code> to be printed
*/
@Override
public void print(
float f)
throws IOException {
write(String.valueOf(f));
}
/**
* Print a double-precision floating-point number. The string produced by
* <code>{@link String#valueOf(double)}</code> is translated into
* bytes according to the platform's default character encoding, and these
* bytes are written in exactly the manner of the <code>{@link
* #write(int)}</code> method.
*
* @param d The <code>double</code> to be printed
*/
@Override
public void print(
double d)
throws IOException {
write(String.valueOf(d));
}
/**
* Print an array of characters. The characters are converted into bytes
* according to the platform's default character encoding, and these bytes
* are written in exactly the manner of the <code>{@link #write(int)}</code>
* method.
*
* @param s The array of chars to be printed
*
* @throws NullPointerException If <code>s</code> is <code>null</code>
*/
@Override
public void print(
char s[])
throws IOException {
write(s);
}
/**
* Print a string. If the argument is <code>null</code> then the string
* <code>"null"</code> is printed. Otherwise, the string's characters are
* converted into bytes according to the platform's default character
* encoding, and these bytes are written in exactly the manner of the
* <code>{@link #write(int)}</code> method.
*
* @param s The <code>String</code> to be printed
*/
@Override
public void print(String s)
throws IOException {
if (s ==
null) {
s =
"null";
}
write(s);
}
/**
* Print an object. The string produced by the <code>{@link
* String#valueOf(Object)}</code> method is translated into bytes
* according to the platform's default character encoding, and these bytes
* are written in exactly the manner of the <code>{@link #write(int)}</code>
* method.
*
* @param obj The <code>Object</code> to be printed
*/
@Override
public void print(Object obj)
throws IOException {
write(String.valueOf(obj));
}
/* Methods that do terminate lines */
/**
* Terminate the current line by writing the line separator string. The
* line separator string is defined by the system property
* <code>line.separator</code>, and is not necessarily a single newline
* character (<code>'\n'</code>).
*
* Need to change this from PrintWriter because the default
* println() writes to the sink directly instead of through the
* write method...
*/
@Override
public void println()
throws IOException {
newLine();
}
/**
* Print a boolean value and then terminate the line. This method behaves
* as though it invokes <code>{@link #print(boolean)}</code> and then
* <code>{@link #println()}</code>.
*/
@Override
public void println(
boolean x)
throws IOException {
print(x);
println();
}
/**
* Print a character and then terminate the line. This method behaves as
* though it invokes <code>{@link #print(char)}</code> and then <code>{@link
* #println()}</code>.
*/
@Override
public void println(
char x)
throws IOException {
print(x);
println();
}
/**
* Print an integer and then terminate the line. This method behaves as
* though it invokes <code>{@link #print(int)}</code> and then <code>{@link
* #println()}</code>.
*/
@Override
public void println(
int x)
throws IOException {
print(x);
println();
}
/**
* Print a long integer and then terminate the line. This method behaves
* as though it invokes <code>{@link #print(long)}</code> and then
* <code>{@link #println()}</code>.
*/
@Override
public void println(
long x)
throws IOException {
print(x);
println();
}
/**
* Print a floating-point number and then terminate the line. This method
* behaves as though it invokes <code>{@link #print(float)}</code> and then
* <code>{@link #println()}</code>.
*/
@Override
public void println(
float x)
throws IOException {
print(x);
println();
}
/**
* Print a double-precision floating-point number and then terminate the
* line. This method behaves as though it invokes <code>{@link
* #print(double)}</code> and then <code>{@link #println()}</code>.
*/
@Override
public void println(
double x)
throws IOException {
print(x);
println();
}
/**
* Print an array of characters and then terminate the line. This method
* behaves as though it invokes <code>{@link #print(char[])}</code> and then
* <code>{@link #println()}</code>.
*/
@Override
public void println(
char x[])
throws IOException {
print(x);
println();
}
/**
* Print a String and then terminate the line. This method behaves as
* though it invokes <code>{@link #print(String)}</code> and then
* <code>{@link #println()}</code>.
*/
@Override
public void println(String x)
throws IOException {
print(x);
println();
}
/**
* Print an Object and then terminate the line. This method behaves as
* though it invokes <code>{@link #print(Object)}</code> and then
* <code>{@link #println()}</code>.
*/
@Override
public void println(Object x)
throws IOException {
print(x);
println();
}
}
