jspcompilationcontext.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;

import java.io.File;
import java.io.FileNotFoundException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import javax.servlet.ServletContext;
import javax.servlet.jsp.tagext.TagInfo;

import org.apache.jasper.compiler.Compiler;
import org.apache.jasper.compiler.JspRuntimeContext;
import org.apache.jasper.compiler.JspUtil;
import org.apache.jasper.compiler.Localizer;
import org.apache.jasper.compiler.ServletWriter;
import org.apache.jasper.servlet.JasperLoader;
import org.apache.jasper.servlet.JspServletWrapper;

/**
 * A place holder for various things that are used through out the JSP
 * engine. This is a per-request/per-context data structure. Some of
 * the instance variables are set at different points.
 *
 * Most of the path-related stuff is here - mangling names, versions, dirs,
 * loading resources and dealing with uris. 
 *
 * @author Anil K. Vijendran
 * @author Harish Prabandham
 * @author Pierre Delisle
 * @author Costin Manolache
 * @author Kin-man Chung
 */
public class JspCompilationContext {

    protected org.apache.juli.logging.Log log =
        org.apache.juli.logging.LogFactory.getLog(JspCompilationContext.class);

    protected Map<String, URL> tagFileJarUrls;
    protected boolean isPackagedTagFile;

    protected String className;
    protected String jspUri;
    protected boolean isErrPage;
    protected String basePackageName;
    protected String derivedPackageName;
    protected String servletJavaFileName;
    protected String javaPath;
    protected String classFileName;
    protected String contentType;
    protected ServletWriter writer;
    protected Options options;
    protected JspServletWrapper jsw;
    protected Compiler jspCompiler;
    protected String classPath;

    protected String baseURI;
    protected String outputDir;
    protected ServletContext context;
    protected URLClassLoader loader;

    protected JspRuntimeContext rctxt;

    protected int removed = 0;

    protected URLClassLoader jspLoader;
    protected URL baseUrl;
    protected Class servletClass;

    protected boolean isTagFile;
    protected boolean protoTypeMode;
    protected TagInfo tagInfo;
    protected URL tagFileJarUrl;

    // jspURI _must_ be relative to the context
    public JspCompilationContext(String jspUri,
                                 boolean isErrPage,
                                 Options options,
                                 ServletContext context,
                                 JspServletWrapper jsw,
                                 JspRuntimeContext rctxt) {

        this.jspUri = canonicalURI(jspUri);
        this.isErrPage = isErrPage;
        this.options = options;
        this.jsw = jsw;
        this.context = context;

        this.baseURI = jspUri.substring(0, jspUri.lastIndexOf('/') + 1);
        // hack fix for resolveRelativeURI
        if (baseURI == null) {
            baseURI = "/";
        } else if (baseURI.charAt(0) != '/') {
            // strip the basde slash since it will be combined with the
            // uriBase to generate a file
            baseURI = "/" + baseURI;
        }
        if (baseURI.charAt(baseURI.length() - 1) != '/') {
            baseURI += '/';
        }

        this.rctxt = rctxt;
        this.tagFileJarUrls = new HashMap<String, URL>();
        this.basePackageName = Constants.JSP_PACKAGE_NAME;
    }

    public JspCompilationContext(String tagfile,
                                 TagInfo tagInfo, 
                                 Options options,
                                 ServletContext context,
                                 JspServletWrapper jsw,
                                 JspRuntimeContext rctxt,
                                 URL tagFileJarUrl) {
        this(tagfile, false, options, context, jsw, rctxt);
        this.isTagFile = true;
        this.tagInfo = tagInfo;
        this.tagFileJarUrl = tagFileJarUrl;
        if (tagFileJarUrl != null) {
            isPackagedTagFile = true;
        }
    }

    /* ==================== Methods to override ==================== */
    
    /** ---------- Class path and loader ---------- */

    /**
     * The classpath that is passed off to the Java compiler. 
     */
    public String getClassPath() {
        if( classPath != null )
            return classPath;
        return rctxt.getClassPath();
    }

    /**
     * The classpath that is passed off to the Java compiler. 
     */
    public void setClassPath(String classPath) {
        this.classPath = classPath;
    }

    /**
     * What class loader to use for loading classes while compiling
     * this JSP?
     */
    public ClassLoader getClassLoader() {
        if( loader != null )
            return loader;
        return rctxt.getParentClassLoader();
    }

    public void setClassLoader(URLClassLoader loader) {
        this.loader = loader;
    }

    public ClassLoader getJspLoader() {
        if( jspLoader == null ) {
            jspLoader = new JasperLoader
            (new URL[] {baseUrl},
                    getClassLoader(),
                    rctxt.getPermissionCollection(),
                    rctxt.getCodeSource());
        }
        return jspLoader;
    }

    /** ---------- Input/Output  ---------- */
    
    /**
     * The output directory to generate code into.  The output directory
     * is make up of the scratch directory, which is provide in Options,
     * plus the directory derived from the package name.
     */
    public String getOutputDir() {
	if (outputDir == null) {
	    createOutputDir();
	}

        return outputDir;
    }

    /**
     * Create a "Compiler" object based on some init param data. This
     * is not done yet. Right now we're just hardcoding the actual
     * compilers that are created. 
     */
    public Compiler createCompiler() throws JasperException {
        if (jspCompiler != null ) {
            return jspCompiler;
        }
        jspCompiler = null;
        if (options.getCompilerClassName() != null) {
            jspCompiler = createCompiler(options.getCompilerClassName());
        } else {
            if (options.getCompiler() == null) {
                jspCompiler = createCompiler("org.apache.jasper.compiler.JDTCompiler");
                if (jspCompiler == null) {
                    jspCompiler = createCompiler("org.apache.jasper.compiler.AntCompiler");
                }
            } else {
                jspCompiler = createCompiler("org.apache.jasper.compiler.AntCompiler");
                if (jspCompiler == null) {
                    jspCompiler = createCompiler("org.apache.jasper.compiler.JDTCompiler");
                }
            }
        }
        if (jspCompiler == null) {
            throw new IllegalStateException(Localizer.getMessage("jsp.error.compiler"));
        }
        jspCompiler.init(this, jsw);
        return jspCompiler;
    }

    protected Compiler createCompiler(String className) {
        Compiler compiler = null; 
        try {
            compiler = (Compiler) Class.forName(className).newInstance();
        } catch (InstantiationException e) {
            log.warn(Localizer.getMessage("jsp.error.compiler"), e);
        } catch (IllegalAccessException e) {
            log.warn(Localizer.getMessage("jsp.error.compiler"), e);
        } catch (NoClassDefFoundError e) {
            if (log.isDebugEnabled()) {
                log.debug(Localizer.getMessage("jsp.error.compiler"), e);
            }
        } catch (ClassNotFoundException e) {
            if (log.isDebugEnabled()) {
                log.debug(Localizer.getMessage("jsp.error.compiler"), e);
            }
        }
        return compiler;
    }
    
    public Compiler getCompiler() {
        return jspCompiler;
    }

    /** ---------- Access resources in the webapp ---------- */

    /** 
     * Get the full value of a URI relative to this compilations context
     * uses current file as the base.
     */
    public String resolveRelativeUri(String uri) {
        // sometimes we get uri's massaged from File(String), so check for
        // a root directory deperator char
        if (uri.startsWith("/") || uri.startsWith(File.separator)) {
            return uri;
        } else {
            return baseURI + uri;
        }
    }

    /**
     * Gets a resource as a stream, relative to the meanings of this
     * context's implementation.
     * @return a null if the resource cannot be found or represented 
     *         as an InputStream.
     */
    public java.io.InputStream getResourceAsStream(String res) {
        return context.getResourceAsStream(canonicalURI(res));
    }


    public URL getResource(String res) throws MalformedURLException {
        return context.getResource(canonicalURI(res));
    }

    public Set getResourcePaths(String path) {
        return context.getResourcePaths(canonicalURI(path));
    }

    /** 
     * Gets the actual path of a URI relative to the context of
     * the compilation.
     */
    public String getRealPath(String path) {
        if (context != null) {
            return context.getRealPath(path);
        }
        return path;
    }

    /**
     * Returns the tag-file-name-to-JAR-file map of this compilation unit,
     * which maps tag file names to the JAR files in which the tag files are
     * packaged.
     *
     * The map is populated when parsing the tag-file elements of the TLDs
     * of any imported taglibs. 
     */
    public URL getTagFileJarUrl(String tagFile) {
        return this.tagFileJarUrls.get(tagFile);
    }

    public void setTagFileJarUrl(String tagFile, URL tagFileURL) {
        this.tagFileJarUrls.put(tagFile, tagFileURL);
    }

    /**
     * Returns the JAR file in which the tag file for which this
     * JspCompilationContext was created is packaged, or null if this
     * JspCompilationContext does not correspond to a tag file, or if the
     * corresponding tag file is not packaged in a JAR.
     */
    public URL getTagFileJarUrl() {
        return this.tagFileJarUrl;
    }

    /* ==================== Common implementation ==================== */

    /**
     * Just the class name (does not include package name) of the
     * generated class. 
     */
    public String getServletClassName() {

        if (className != null) {
            return className;
        }

        if (isTagFile) {
            className = tagInfo.getTagClassName();
            int lastIndex = className.lastIndexOf('.');
            if (lastIndex != -1) {
                className = className.substring(lastIndex + 1);
            }
        } else {
            int iSep = jspUri.lastIndexOf('/') + 1;
            className = JspUtil.makeJavaIdentifier(jspUri.substring(iSep));
        }
        return className;
    }

    public void setServletClassName(String className) {
        this.className = className;
    }
    
    /**