jspruntimecontext.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.File;
import java.io.FileNotFoundException;
import java.io.FilePermission;
import java.net.URL;
import java.net.URLClassLoader;
import java.security.CodeSource;
import java.security.PermissionCollection;
import java.security.Policy;
import java.security.cert.Certificate;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import javax.servlet.ServletContext;
import javax.servlet.jsp.JspFactory;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.jasper.Constants;
import org.apache.jasper.JspCompilationContext;
import org.apache.jasper.Options;
import org.apache.jasper.runtime.JspFactoryImpl;
import org.apache.jasper.security.SecurityClassLoad;
import org.apache.jasper.servlet.JspServletWrapper;

/**
 * Class for tracking JSP compile time file dependencies when the
 * &060;%@include file="..."%&062; directive is used.
 *
 * A background thread periodically checks the files a JSP page
 * is dependent upon.  If a dpendent file changes the JSP page
 * which included it is recompiled.
 *
 * Only used if a web application context is a directory.
 *
 * @author Glenn L. Nielsen
 * @version $Revision: 306189 $
 */
public final class JspRuntimeContext implements Runnable {

    // Logger
    private Log log = LogFactory.getLog(JspRuntimeContext.class);

    /*
     * Counts how many times the webapp's JSPs have been reloaded.
     */
    private int jspReloadCount;

    /**
     * Preload classes required at runtime by a JSP servlet so that
     * we don't get a defineClassInPackage security exception.
     */
    static {
        JspFactoryImpl factory = new JspFactoryImpl();
        SecurityClassLoad.securityClassLoad(factory.getClass().getClassLoader());
        JspFactory.setDefaultFactory(factory);
    }

    // ----------------------------------------------------------- Constructors

    /**
     * Create a JspRuntimeContext for a web application context.
     *
     * Loads in any previously generated dependencies from file.
     *
     * @param context ServletContext for web application
     */
    public JspRuntimeContext(ServletContext context, Options options) {

        this.context = context;
        this.options = options;

        // Get the parent class loader
        parentClassLoader =
            (URLClassLoader) Thread.currentThread().getContextClassLoader();
        if (parentClassLoader == null) {
            parentClassLoader =
                (URLClassLoader)this.getClass().getClassLoader();
        }

	if (log.isDebugEnabled()) {
	    if (parentClassLoader != null) {
		log.debug(Localizer.getMessage("jsp.message.parent_class_loader_is",
					       parentClassLoader.toString()));
	    } else {
		log.debug(Localizer.getMessage("jsp.message.parent_class_loader_is",
					       "<none>"));
	    }
        }

        initClassPath();

	if (context instanceof org.apache.jasper.servlet.JspCServletContext) {
	    return;
	}

        if (System.getSecurityManager() != null) {
            initSecurity();
        }

        // If this web application context is running from a
        // directory, start the background compilation thread
        String appBase = context.getRealPath("/");         
        if (!options.getDevelopment()
                && appBase != null
                && options.getCheckInterval() > 0) {
            if (appBase.endsWith(File.separator) ) {
                appBase = appBase.substring(0,appBase.length()-1);
            }
            String directory =
                appBase.substring(appBase.lastIndexOf(File.separator));
            threadName = threadName + "[" + directory + "]";
            threadStart();
        }                                            
    }

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

    /**
     * This web applications ServletContext
     */
    private ServletContext context;
    private Options options;
    private URLClassLoader parentClassLoader;
    private PermissionCollection permissionCollection;
    private CodeSource codeSource;                    
    private String classpath;

    /**
     * Maps JSP pages to their JspServletWrapper's
     */
    private Map jsps = Collections.synchronizedMap( new HashMap());
 

    /**
     * The background thread.
     */
    private Thread thread = null;


    /**
     * The background thread completion semaphore.
     */
    private boolean threadDone = false;


    /**
     * Name to register for the background thread.
     */
    private String threadName = "JspRuntimeContext";

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

    /**
     * Add a new JspServletWrapper.
     *
     * @param jspUri JSP URI
     * @param jsw Servlet wrapper for JSP
     */
    public void addWrapper(String jspUri, JspServletWrapper jsw) {
        jsps.remove(jspUri);
        jsps.put(jspUri,jsw);
    }

    /**
     * Get an already existing JspServletWrapper.
     *
     * @param jspUri JSP URI
     * @return JspServletWrapper for JSP
     */
    public JspServletWrapper getWrapper(String jspUri) {
        return (JspServletWrapper) jsps.get(jspUri);
    }

    /**
     * Remove a  JspServletWrapper.
     *
     * @param jspUri JSP URI of JspServletWrapper to remove
     */
    public void removeWrapper(String jspUri) {
        jsps.remove(jspUri);
    }

    /**
     * Returns the number of JSPs for which JspServletWrappers exist, i.e.,
     * the number of JSPs that have been loaded into the webapp.
     *
     * @return The number of JSPs that have been loaded into the webapp
     */
    public int getJspCount() {
        return jsps.size();
    }

    /**
     * Get the SecurityManager Policy CodeSource for this web
     * applicaiton context.
     *
     * @return CodeSource for JSP
     */
    public CodeSource getCodeSource() {
        return codeSource;
    }

    /**
     * Get the parent URLClassLoader.
     *
     * @return URLClassLoader parent
     */
    public URLClassLoader getParentClassLoader() {
        return parentClassLoader;
    }

    /**
     * Get the SecurityManager PermissionCollection for this
     * web application context.
     *
     * @return PermissionCollection permissions
     */
    public PermissionCollection getPermissionCollection() {
        return permissionCollection;
    }

    /**
     * Process a "destory" event for this web application context.
     */                                                        
    public void destroy() {
        threadStop();

        Iterator servlets = jsps.values().iterator();
        while (servlets.hasNext()) {
            ((JspServletWrapper) servlets.next()).destroy();
        }
    }

    /**
     * Increments the JSP reload counter.
     */
    public synchronized void incrementJspReloadCount() {
        jspReloadCount++;
    }

    /**
     * Resets the JSP reload counter.
     *