compiler.java

业界著名的tomcat服务器的最新6.0的源代码。

/*
 * 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.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.net.URLConnection;
import java.util.Iterator;
import java.util.List;

import org.apache.jasper.JasperException;
import org.apache.jasper.JspCompilationContext;
import org.apache.jasper.Options;
import org.apache.jasper.servlet.JspServletWrapper;

/**
 * Main JSP compiler class. This class uses Ant for compiling.
 * 
 * @author Anil K. Vijendran
 * @author Mandar Raje
 * @author Pierre Delisle
 * @author Kin-man Chung
 * @author Remy Maucherat
 * @author Mark Roth
 */
public abstract class Compiler {
    
    protected org.apache.juli.logging.Log log = org.apache.juli.logging.LogFactory
            .getLog(Compiler.class);

    // ----------------------------------------------------- Instance Variables

    protected JspCompilationContext ctxt;

    protected ErrorDispatcher errDispatcher;

    protected PageInfo pageInfo;

    protected JspServletWrapper jsw;

    protected TagFileProcessor tfp;

    protected Options options;

    protected Node.Nodes pageNodes;

    // ------------------------------------------------------------ Constructor

    public void init(JspCompilationContext ctxt, JspServletWrapper jsw) {
        this.jsw = jsw;
        this.ctxt = ctxt;
        this.options = ctxt.getOptions();
    }

    // --------------------------------------------------------- Public Methods

    /**
     * <p>
     * Retrieves the parsed nodes of the JSP page, if they are available. May
     * return null. Used in development mode for generating detailed error
     * messages. http://issues.apache.org/bugzilla/show_bug.cgi?id=37062.
     * </p>
     */
    public Node.Nodes getPageNodes() {
        return this.pageNodes;
    }

    /**
     * Compile the jsp file into equivalent servlet in .java file
     * 
     * @return a smap for the current JSP page, if one is generated, null
     *         otherwise
     */
    protected String[] generateJava() throws Exception {

        String[] smapStr = null;

        long t1, t2, t3, t4;

        t1 = t2 = t3 = t4 = 0;

        if (log.isDebugEnabled()) {
            t1 = System.currentTimeMillis();
        }

        // Setup page info area
        pageInfo = new PageInfo(new BeanRepository(ctxt.getClassLoader(),
                errDispatcher), ctxt.getJspFile());

        JspConfig jspConfig = options.getJspConfig();
        JspConfig.JspProperty jspProperty = jspConfig.findJspProperty(ctxt
                .getJspFile());

        /*
         * If the current uri is matched by a pattern specified in a
         * jsp-property-group in web.xml, initialize pageInfo with those
         * properties.
         */
        if (jspProperty.isELIgnored() != null) {
            pageInfo.setELIgnored(JspUtil.booleanValue(jspProperty
                    .isELIgnored()));
        }
        if (jspProperty.isScriptingInvalid() != null) {
            pageInfo.setScriptingInvalid(JspUtil.booleanValue(jspProperty
                    .isScriptingInvalid()));
        }
        if (jspProperty.getIncludePrelude() != null) {
            pageInfo.setIncludePrelude(jspProperty.getIncludePrelude());
        }
        if (jspProperty.getIncludeCoda() != null) {
            pageInfo.setIncludeCoda(jspProperty.getIncludeCoda());
        }
        if (jspProperty.isDeferedSyntaxAllowedAsLiteral() != null) {
            pageInfo.setDeferredSyntaxAllowedAsLiteral(JspUtil.booleanValue(jspProperty
                    .isDeferedSyntaxAllowedAsLiteral()));
        }
        if (jspProperty.isTrimDirectiveWhitespaces() != null) {
            pageInfo.setTrimDirectiveWhitespaces(JspUtil.booleanValue(jspProperty
                    .isTrimDirectiveWhitespaces()));
        }

        ctxt.checkOutputDir();
        String javaFileName = ctxt.getServletJavaFileName();
        ServletWriter writer = null;

        try {
            // Setup the ServletWriter
            String javaEncoding = ctxt.getOptions().getJavaEncoding();
            OutputStreamWriter osw = null;

            try {
                osw = new OutputStreamWriter(
                        new FileOutputStream(javaFileName), javaEncoding);
            } catch (UnsupportedEncodingException ex) {
                errDispatcher.jspError("jsp.error.needAlternateJavaEncoding",
                        javaEncoding);
            }

            writer = new ServletWriter(new PrintWriter(osw));
            ctxt.setWriter(writer);

            // Reset the temporary variable counter for the generator.
            JspUtil.resetTemporaryVariableName();

            // Parse the file
            ParserController parserCtl = new ParserController(ctxt, this);
            pageNodes = parserCtl.parse(ctxt.getJspFile());

            if (ctxt.isPrototypeMode()) {
                // generate prototype .java file for the tag file
                Generator.generate(writer, this, pageNodes);
                writer.close();
                writer = null;
                return null;
            }

            // Validate and process attributes
            Validator.validate(this, pageNodes);

            if (log.isDebugEnabled()) {
                t2 = System.currentTimeMillis();
            }

            // Collect page info
            Collector.collect(this, pageNodes);

            // Compile (if necessary) and load the tag files referenced in
            // this compilation unit.
            tfp = new TagFileProcessor();
            tfp.loadTagFiles(this, pageNodes);

            if (log.isDebugEnabled()) {
                t3 = System.currentTimeMillis();
            }

            // Determine which custom tag needs to declare which scripting vars
            ScriptingVariabler.set(pageNodes, errDispatcher);

            // Optimizations by Tag Plugins
            TagPluginManager tagPluginManager = options.getTagPluginManager();
            tagPluginManager.apply(pageNodes, errDispatcher, pageInfo);

            // Optimization: concatenate contiguous template texts.
            TextOptimizer.concatenate(this, pageNodes);

            // Generate static function mapper codes.
            ELFunctionMapper.map(this, pageNodes);

            // generate servlet .java file
            Generator.generate(writer, this, pageNodes);
            writer.close();
            writer = null;

            // The writer is only used during the compile, dereference
            // it in the JspCompilationContext when done to allow it
            // to be GC'd and save memory.
            ctxt.setWriter(null);

            if (log.isDebugEnabled()) {
                t4 = System.currentTimeMillis();
                log.debug("Generated " + javaFileName + " total=" + (t4 - t1)
                        + " generate=" + (t4 - t3) + " validate=" + (t2 - t1));
            }

        } catch (Exception e) {
            if (writer != null) {
                try {
                    writer.close();
                    writer = null;
                } catch (Exception e1) {
                    // do nothing
                }
            }
            // Remove the generated .java file
            new File(javaFileName).delete();
            throw e;
        } finally {
            if (writer != null) {
                try {
                    writer.close();
                } catch (Exception e2) {
                    // do nothing
                }
            }
        }

        // JSR45 Support
        if (!options.isSmapSuppressed()) {
            smapStr = SmapUtil.generateSmap(ctxt, pageNodes);
        }

        // If any proto type .java and .class files was generated,
        // the prototype .java may have been replaced by the current