parsercontroller.java

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/*
 * Copyright 1999,2004 The Apache Software Foundation.
 * 
 * Licensed 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.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.JarURLConnection;
import java.net.URL;
import java.util.Stack;
import java.util.jar.JarFile;

import org.apache.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;
import org.apache.jasper.xmlparser.XMLEncodingDetector;
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 JspCompilationContext ctxt;
    private Compiler compiler;
    private 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 Stack baseDirStack = new Stack();
    
    private boolean isEncodingSpecifiedInProlog;

    private String sourceEnc;

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

    /*
     * Constructor
     */
    public 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.
     */
    public Node.Nodes parse(String inFileName)
	        throws FileNotFoundException, 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.getTagFileJarUrl());
    }

    /**
     * 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 jarFile The JAR file from which to read the included resource,
     * or null of the included resource is to be read from the filesystem
     */
    public Node.Nodes parse(String inFileName, Node parent,
			    URL jarFileUrl)
	        throws FileNotFoundException, JasperException, IOException {
        // For files that are statically included, isTagfile and directiveOnly
        // remain unchanged.
        return doParse(inFileName, parent, jarFileUrl);
    }

    /**
     * Extracts tag file directive information from the tag file with the
     * given name.
     *
     * This is invoked by the compiler 
     *
     * @param inFileName The name of the tag file to be parsed.
     */
    public Node.Nodes parseTagFileDirectives(String inFileName)
	        throws FileNotFoundException, JasperException, IOException {
        boolean isTagFileSave = isTagFile;
        boolean directiveOnlySave = directiveOnly;
        isTagFile = true;
        directiveOnly = true;
        Node.Nodes page = doParse(inFileName, null,
                             (URL) ctxt.getTagFileJarUrls().get(inFileName));
        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 isTagFile true if file to be parsed is tag file, and false if it
     * is a regular JSP page
     * @param directivesOnly true if the file to be parsed is a tag file and
     * we are only interested in the directives needed for constructing a
     * TagFileInfo.
     * @param jarFile 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,
                               URL jarFileUrl)
	        throws FileNotFoundException, JasperException, IOException {

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

	JarFile jarFile = getJarFile(jarFileUrl);
	String absFileName = resolveFileName(inFileName);
	String jspConfigPageEnc = getJspConfigPageEncoding(absFileName);

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

	if (parent != null) {
	    // Included resource, add to dependent list
	    compiler.getPageInfo().addDependant(absFileName);
	}

	if (isXml && isEncodingSpecifiedInProlog) {
	    /*
	     * 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,
                                                 jarFile, parent,
                                                 isTagFile, directiveOnly,
                                                 sourceEnc,
                                                 jspConfigPageEnc,
                                                 isEncodingSpecifiedInProlog);
	} else {
	    // Standard syntax
	    InputStreamReader inStreamReader = null;
	    try {
		inStreamReader = JspUtil.getReader(absFileName, sourceEnc,
						   jarFile, ctxt, err);
		JspReader jspReader = new JspReader(ctxt, absFileName,
						    sourceEnc, inStreamReader,
						    err);
                parsedPage = Parser.parse(this, jspReader, parent, isTagFile,
					  directiveOnly, jarFileUrl,
					  sourceEnc, jspConfigPageEnc,
					  isDefaultPageEncoding);
            } finally {
		if (inStreamReader != null) {
		    try {
			inStreamReader.close();
		    } catch (Exception any) {
		    }
		}
	    }
	}

	if (jarFile != null) {
	    try {
		jarFile.close();
	    } catch (Throwable t) {}
	}

	baseDirStack.pop();

	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)
            throws JasperException {

	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,
					    JarFile jarFile,
					    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;
	}