Quelle ParserController.java Sprache: JAVA

/*
* 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.compiler;

import java.io.BufferedInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayDeque;
import java.util.Deque;

import org.apache.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;
import org.apache.tomcat.Jar;
import org.xml.sax.Attributes;

/**
* Controller for the parsing of a JSP page.
* <p>
* The same ParserController instance is used for a JSP page and any JSP
* segments included by it (via an include directive), where each segment may
* be provided in standard or XML syntax. This class selects and invokes the
* appropriate parser for the JSP page and its included segments.
*
* @author Pierre Delisle
* @author Jan Luehe
*/
class ParserController implements TagConstants {

    private static final String CHARSET = "charset=";

    private final JspCompilationContext ctxt;
    private final Compiler compiler;
    private final ErrorDispatcher err;

    /*
     * Indicates the syntax (XML or standard) of the file being processed
     */
    private boolean isXml;

    /*
     * A stack to keep track of the 'current base directory'
     * for include directives that refer to relative paths.
     */
    private final Deque<String> baseDirStack = new ArrayDeque<>();

    private boolean isEncodingSpecifiedInProlog;
    private boolean isBomPresent;
    private int skip;

    private String sourceEnc;

    private boolean isDefaultPageEncoding;
    private boolean isTagFile;
    private boolean directiveOnly;

    /*
     * Constructor
     */
    ParserController(JspCompilationContext ctxt, Compiler compiler) {
        this.ctxt = ctxt;
        this.compiler = compiler;
        this.err = compiler.getErrorDispatcher();
    }

    public JspCompilationContext getJspCompilationContext () {
        return ctxt;
    }

    public Compiler getCompiler () {
        return compiler;
    }

    /**
     * Parses a JSP page or tag file. This is invoked by the compiler.
     *
     * @param inFileName The path to the JSP page or tag file to be parsed.
     *
     * @return The parsed nodes
     *
     * @throws JasperException If an error occurs during parsing
     * @throws IOException If an I/O error occurs such as the file not being
     *         found
     */
    public Node.Nodes parse(String inFileName) throws JasperException, IOException {
        // If we're parsing a packaged tag file or a resource included by it
        // (using an include directive), ctxt.getTagFileJar() returns the
        // JAR file from which to read the tag file or included resource,
        // respectively.
        isTagFile = ctxt.isTagFile();
        directiveOnly = false;
        return doParse(inFileName, null, ctxt.getTagFileJar());
    }

    /**
     * Parses the directives of a JSP page or tag file. This is invoked by the
     * compiler.
     *
     * @param inFileName The path to the JSP page or tag file to be parsed.
     *
     * @return The parsed directive nodes
     *
     * @throws JasperException If an error occurs during parsing
     * @throws IOException If an I/O error occurs such as the file not being
     *         found
     */
    public Node.Nodes parseDirectives(String inFileName) throws JasperException, IOException {
        // If we're parsing a packaged tag file or a resource included by it
        // (using an include directive), ctxt.getTagFileJar() returns the
        // JAR file from which to read the tag file or included resource,
        // respectively.
        isTagFile = ctxt.isTagFile();
        directiveOnly = true;
        return doParse(inFileName, null, ctxt.getTagFileJar());
    }

    /**
     * Processes an include directive with the given path.
     *
     * @param inFileName The path to the resource to be included.
     * @param parent The parent node of the include directive.
     * @param jar The JAR file from which to read the included resource,
     * or null of the included resource is to be read from the filesystem
     *
     * @return The parsed nodes
     *
     * @throws JasperException If an error occurs during parsing
     * @throws IOException If an I/O error occurs such as the file not being
     *         found
     */
    public Node.Nodes parse(String inFileName, Node parent, Jar jar)
            throws JasperException, IOException {
        // For files that are statically included, isTagfile and directiveOnly
        // remain unchanged.
        return doParse(inFileName, parent, jar);
    }

    /**
     * Extracts tag file directive information from the given tag file.
     *
     * This is invoked by the compiler
     *
     * @param inFileName    The name of the tag file to be parsed.
     * @param jar The location of the tag file.
     *
     * @return The parsed tag file nodes
     *
     * @throws JasperException If an error occurs during parsing
     * @throws IOException If an I/O error occurs such as the file not being
     *         found
     */
    public Node.Nodes parseTagFileDirectives(String inFileName, Jar jar)
            throws JasperException, IOException {
        boolean isTagFileSave = isTagFile;
        boolean directiveOnlySave = directiveOnly;
        isTagFile = true;
        directiveOnly = true;
        Node.Nodes page = doParse(inFileName, null, jar);
        directiveOnly = directiveOnlySave;
        isTagFile = isTagFileSave;
        return page;
    }

    /**
     * Parses the JSP page or tag file with the given path name.
     *
     * @param inFileName The name of the JSP page or tag file to be parsed.
     * @param parent The parent node (non-null when processing an include
     * directive)
     * @param jar  The JAR file from which to read the JSP page or tag file,
     * or null if the JSP page or tag file is to be read from the filesystem
     */
    private Node.Nodes doParse(String inFileName, Node parent, Jar jar)
            throws FileNotFoundException, JasperException, IOException {

        Node.Nodes parsedPage = null;
        isEncodingSpecifiedInProlog = false;
        isBomPresent = false;
        isDefaultPageEncoding = false;

        String absFileName = resolveFileName(inFileName);
        String jspConfigPageEnc = getJspConfigPageEncoding(absFileName);

        // Figure out what type of JSP document and encoding type we are
        // dealing with
        determineSyntaxAndEncoding(absFileName, jar, jspConfigPageEnc);

        if (parent != null) {
            // Included resource, add to dependent list
            if (jar == null) {
                compiler.getPageInfo().addDependant(absFileName,
                        ctxt.getLastModified(absFileName));
            } else {
                String entry = absFileName.substring(1);
                compiler.getPageInfo().addDependant(jar.getURL(entry),
                        Long.valueOf(jar.getLastModified(entry)));

            }
        }

        if ((isXml && isEncodingSpecifiedInProlog) || isBomPresent) {
            /*
             * Make sure the encoding explicitly specified in the XML
             * prolog (if any) matches that in the JSP config element
             * (if any), treating "UTF-16", "UTF-16BE", and "UTF-16LE" as
             * identical.
             */
            if (jspConfigPageEnc != null && !jspConfigPageEnc.equals(sourceEnc)
                    && (!jspConfigPageEnc.startsWith("UTF-16")
                            || !sourceEnc.startsWith("UTF-16"))) {
                err.jspError("jsp.error.prolog_config_encoding_mismatch",
                        sourceEnc, jspConfigPageEnc);
            }
        }

        // Dispatch to the appropriate parser
        if (isXml) {
            // JSP document (XML syntax)
            // InputStream for jspx page is created and properly closed in
            // JspDocumentParser.
            parsedPage = JspDocumentParser.parse(this, absFileName, jar, parent,
                    isTagFile, directiveOnly, sourceEnc, jspConfigPageEnc,
                    isEncodingSpecifiedInProlog, isBomPresent);
        } else {
            // Standard syntax
            try (InputStreamReader inStreamReader = JspUtil.getReader(
                    absFileName, sourceEnc, jar, ctxt, err, skip)) {
                JspReader jspReader = new JspReader(ctxt, absFileName,
                        inStreamReader, err);
                parsedPage = Parser.parse(this, jspReader, parent, isTagFile,
                        directiveOnly, jar, sourceEnc, jspConfigPageEnc,
                        isDefaultPageEncoding, isBomPresent);
            }
        }

        baseDirStack.remove();

        return parsedPage;
    }

    /*
     * Checks to see if the given URI is matched by a URL pattern specified in
     * a jsp-property-group in web.xml, and if so, returns the value of the
     * <page-encoding> element.
     *
     * @param absFileName The URI to match
     *
     * @return The value of the <page-encoding> attribute of the
     * jsp-property-group with matching URL pattern
     */
    private String getJspConfigPageEncoding(String absFileName) {

        JspConfig jspConfig = ctxt.getOptions().getJspConfig();
        JspConfig.JspProperty jspProperty
            = jspConfig.findJspProperty(absFileName);
        return jspProperty.getPageEncoding();
    }

    /**
     * Determines the syntax (standard or XML) and page encoding properties
     * for the given file, and stores them in the 'isXml' and 'sourceEnc'
     * instance variables, respectively.
     */
    private void determineSyntaxAndEncoding(String absFileName, Jar jar,
            String jspConfigPageEnc)
    throws JasperException, IOException {

        isXml = false;

        /*
         * 'true' if the syntax (XML or standard) of the file is given
         * from external information: either via a JSP configuration element,
         * the ".jspx" suffix, or the enclosing file (for included resources)
         */
        boolean isExternal = false;

        /*
         * Indicates whether we need to revert from temporary usage of
         * "ISO-8859-1" back to "UTF-8"
         */
        boolean revert = false;

        JspConfig jspConfig = ctxt.getOptions().getJspConfig();
        JspConfig.JspProperty jspProperty = jspConfig.findJspProperty(
                absFileName);
        if (jspProperty.isXml() != null) {
            // If <is-xml> is specified in a <jsp-property-group>, it is used.
            isXml = JspUtil.booleanValue(jspProperty.isXml());
            isExternal = true;
        } else if (absFileName.endsWith(".jspx")
                || absFileName.endsWith(".tagx")) {
            isXml = true;
            isExternal = true;
        }

        if (isExternal && !isXml) {
            // JSP (standard) syntax. Use encoding specified in jsp-config
            // if provided.
            sourceEnc = jspConfigPageEnc;
            if (sourceEnc != null) {
                return;
            }
            // We don't know the encoding, so use BOM to determine it
            sourceEnc = "ISO-8859-1";
        } else {
            // XML syntax or unknown, (auto)detect encoding ...
            EncodingDetector encodingDetector;
            try (BufferedInputStream bis = JspUtil.getInputStream(absFileName, jar, ctxt)) {
                encodingDetector = new EncodingDetector(bis);
            }

            sourceEnc = encodingDetector.getEncoding();
            isEncodingSpecifiedInProlog = encodingDetector.isEncodingSpecifiedInProlog();
            isBomPresent = (encodingDetector.getSkip() > 0);
            skip = encodingDetector.getSkip();

            if (!isXml && sourceEnc.equals("UTF-8")) {
                /*
                 * We don't know if we're dealing with XML or standard syntax.
                 * Therefore, we need to check to see if the page contains
                 * a <jsp:root> element.
                 *
                 * We need to be careful, because the page may be encoded in
                 * ISO-8859-1 (or something entirely different), and may
                 * contain byte sequences that will cause a UTF-8 converter to
                 * throw exceptions.
                 *
                 * It is safe to use a source encoding of ISO-8859-1 in this
                 * case, as there are no invalid byte sequences in ISO-8859-1,
                 * and the byte/character sequences we're looking for (i.e.,
                 * <jsp:root>) are identical in either encoding (both UTF-8
                 * and ISO-8859-1 are extensions of ASCII).
                 */
                sourceEnc = "ISO-8859-1";
                revert = true;
            }
        }

        if (isXml) {
            // (This implies 'isExternal' is TRUE.)
            // We know we're dealing with a JSP document (via JSP config or
            // ".jspx" suffix), so we're done.
            return;
        }

        /*
         * At this point, 'isExternal' or 'isXml' is FALSE.
         * Search for jsp:root action, in order to determine if we're dealing
         * with XML or standard syntax (unless we already know what we're
         * dealing with, i.e., when 'isExternal' is TRUE and 'isXml' is FALSE).
         * No check for XML prolog, since nothing prevents a page from
         * outputting XML and still using JSP syntax (in this case, the
         * XML prolog is treated as template text).
         */
        JspReader jspReader = null;
        try {
            jspReader = new JspReader(ctxt, absFileName, sourceEnc, jar, err);
        } catch (FileNotFoundException ex) {
            throw new JasperException(ex);
        }
        Mark startMark = jspReader.mark();
        if (!isExternal) {
            jspReader.reset(startMark);
            if (hasJspRoot(jspReader)) {
                if (revert) {
                    sourceEnc = "UTF-8";
                }
                isXml = true;
                return;
            } else {
                if (revert && isBomPresent) {
                    sourceEnc = "UTF-8";
                }
                isXml = false;
            }
        }

        /*
         * At this point, we know we're dealing with JSP syntax.
         * If an XML prolog is provided, it's treated as template text.
         * Determine the page encoding from the page directive, unless it's
         * specified via JSP config.
         */
        if (!isBomPresent) {
            sourceEnc = jspConfigPageEnc;
            if (sourceEnc == null) {
                sourceEnc = getPageEncodingForJspSyntax(jspReader, startMark);
                if (sourceEnc == null) {
                    // Default to "ISO-8859-1" per JSP spec
                    sourceEnc = "ISO-8859-1";
                    isDefaultPageEncoding = true;
                }
            }
        }

    }

    /*
     * Determines page source encoding for page or tag file in JSP syntax,
     * by reading (in this order) the value of the 'pageEncoding' page
     * directive attribute, or the charset value of the 'contentType' page
     * directive attribute.
     *
     * @return The page encoding, or null if not found
     */
    private String getPageEncodingForJspSyntax(JspReader jspReader,
            Mark startMark)
    throws JasperException {

        String encoding = null;
        String saveEncoding = null;

        jspReader.reset(startMark);

        /*
         * Determine page encoding from directive of the form <%@ page %>,
         * <%@ tag %>, <jsp:directive.page > or <jsp:directive.tag >.
         */
        while (true) {
            if (jspReader.skipUntil("<") == null) {
                break;
            }
            // If this is a comment, skip until its end
            if (jspReader.matches("%--")) {
                if (jspReader.skipUntil("--%>") == null) {
                    // error will be caught in Parser
                    break;
                }
                continue;
            }
            boolean isDirective = jspReader.matches("%@");
            if (isDirective) {
                jspReader.skipSpaces();
            } else {
                isDirective = jspReader.matches("jsp:directive.");
            }
            if (!isDirective) {
                continue;
            }

            // Want to match tag and page but not taglib
            if (jspReader.matches("tag") && !jspReader.matches("lib") || jspReader.matches("page")) {

                jspReader.skipSpaces();
                Attributes attrs = Parser.parseAttributes(this, jspReader);
                encoding = getPageEncodingFromDirective(attrs, "pageEncoding");
                if (encoding != null) {
                    break;
                }
                encoding = getPageEncodingFromDirective(attrs, "contentType");
                if (encoding != null) {
                    saveEncoding = encoding;
                }
            }
        }

        if (encoding == null) {
            encoding = saveEncoding;
        }

        return encoding;
    }

    /*
     * Scans the given attributes for the attribute with the given name,
     * which is either 'pageEncoding' or 'contentType', and returns the
     * specified page encoding.
     *
     * In the case of 'contentType', the page encoding is taken from the
     * content type's 'charset' component.
     *
     * @param attrs The page directive attributes
     * @param attrName The name of the attribute to search for (either
     * 'pageEncoding' or 'contentType')
     *
     * @return The page encoding, or null
     */
    private String getPageEncodingFromDirective(Attributes attrs,
            String attrName) {
        String value = attrs.getValue(attrName);
        if (attrName.equals("pageEncoding")) {
            return value;
        }

        // attrName = contentType
        String contentType = value;
        String encoding = null;
        if (contentType != null) {
            int loc = contentType.indexOf(CHARSET);
            if (loc != -1) {
                encoding = contentType.substring(loc + CHARSET.length());
            }
        }

        return encoding;
    }

    /*
     * Resolve the name of the file and update baseDirStack() to keep track of
     * the current base directory for each included file.
     * The 'root' file is always an 'absolute' path, so no need to put an
     * initial value in the baseDirStack.
     */
    private String resolveFileName(String inFileName) {
        String fileName = inFileName.replace('\\', '/');
        boolean isAbsolute = fileName.startsWith("/");
        fileName = isAbsolute ? fileName : baseDirStack.peekFirst() + fileName;
        String baseDir = fileName.substring(0, fileName.lastIndexOf('/') + 1);
        baseDirStack.addFirst(baseDir);
        return fileName;
    }

    /*
     * Checks to see if the given page contains, as its first element, a <root>
     * element whose prefix is bound to the JSP namespace, as in:
     *
     * <wombat:root xmlns:wombat="http://java.sun.com/JSP/Page" version="1.2">
     *   ...
     * </wombat:root>
     *
     * @param reader The reader for this page
     *
     * @return true if this page contains a root element whose prefix is bound
     * to the JSP namespace, and false otherwise
     */
    private boolean hasJspRoot(JspReader reader) {

        // <prefix>:root must be the first element
        Mark start = null;
        while ((start = reader.skipUntil("<")) != null) {
            int c = reader.nextChar();
            if (c != '!' && c != '?') {
                break;
            }
        }
        if (start == null) {
            return false;
        }
        Mark stop = reader.skipUntil(":root");
        if (stop == null) {
            return false;
        }
        // call substring to get rid of leading '<'
        String prefix = reader.getText(start, stop).substring(1);

        start = stop;
        stop = reader.skipUntil(">");
        if (stop == null) {
            return false;
        }

        // Determine namespace associated with <root> element's prefix
        String root = reader.getText(start, stop);
        String xmlnsDecl = "xmlns:" + prefix;
        int index = root.indexOf(xmlnsDecl);
        if (index == -1) {
            return false;
        }
        index += xmlnsDecl.length();
        while (index < root.length()
                && Character.isWhitespace(root.charAt(index))) {
            index++;
        }
        if (index < root.length() && root.charAt(index) == '=') {
            index++;
            while (index < root.length()
                    && Character.isWhitespace(root.charAt(index))) {
                index++;
            }
            if (index < root.length()
                && (root.charAt(index) == '"' || root.charAt(index) == '\'')) {
                index++;
                if (root.regionMatches(index, JSP_URI, 0, JSP_URI.length())) {
                    return true;
                }
            }
        }

        return false;
    }
}

quality88%

¤ Dauer der Verarbeitung: 0.16 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.