compiler.java

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/*
 * Copyright 1999,2004-2005 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.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.commons.logging.Log log=
        org.apache.commons.logging.LogFactory.getLog( Compiler.class );

    // ----------------------------------------------------------------- Static


    // Some javac are not thread safe; use a lock to serialize compilation, 
    static Object javacLock = new Object();


    // ----------------------------------------------------- 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.
         */
        pageInfo.setELIgnored(JspUtil.booleanValue(
                                            jspProperty.isELIgnored()));
        pageInfo.setScriptingInvalid(JspUtil.booleanValue(
                                            jspProperty.isScriptingInvalid()));
        if (jspProperty.getIncludePrelude() != null) {
            pageInfo.setIncludePrelude(jspProperty.getIncludePrelude());
        }
        if (jspProperty.getIncludeCoda() != null) {
	    pageInfo.setIncludeCoda(jspProperty.getIncludeCoda());
        }

        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
        // compilation (if the tag file is self referencing), but the
        // .class file need to be removed, to make sure that javac would
        // generate .class again from the new .java file just generated.
        tfp.removeProtoTypeFiles(ctxt.getClassFileName());

        return smapStr;
    }

    /**