applicationcontextfacade.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.catalina.core;


import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.net.URL;
import java.security.AccessController;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Set;

import javax.servlet.RequestDispatcher;
import javax.servlet.Servlet;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;

import org.apache.catalina.Globals;
import org.apache.catalina.security.SecurityUtil;


/**
 * Facade object which masks the internal <code>ApplicationContext</code>
 * object from the web application.
 *
 * @author Remy Maucherat
 * @author Jean-Francois Arcand
 * @version $Revision: 505593 $ $Date: 2007-02-10 01:54:56 +0100 (sam., 10 févr. 2007) $
 */

public final class ApplicationContextFacade
    implements ServletContext {
        
    // ---------------------------------------------------------- Attributes
    /**
     * Cache Class object used for reflection.
     */
    private HashMap classCache;
    
    
    /**
     * Cache method object.
     */
    private HashMap objectCache;
    
    
    // ----------------------------------------------------------- Constructors


    /**
     * Construct a new instance of this class, associated with the specified
     * Context instance.
     *
     * @param context The associated Context instance
     */
    public ApplicationContextFacade(ApplicationContext context) {
        super();
        this.context = context;
        
        classCache = new HashMap();
        objectCache = new HashMap();
        initClassCache();
    }
    
    
    private void initClassCache(){
        Class[] clazz = new Class[]{String.class};
        classCache.put("getContext", clazz);
        classCache.put("getMimeType", clazz);
        classCache.put("getResourcePaths", clazz);
        classCache.put("getResource", clazz);
        classCache.put("getResourceAsStream", clazz);
        classCache.put("getRequestDispatcher", clazz);
        classCache.put("getNamedDispatcher", clazz);
        classCache.put("getServlet", clazz);
        classCache.put("getInitParameter", clazz);
        classCache.put("setAttribute", new Class[]{String.class, Object.class});
        classCache.put("removeAttribute", clazz);
        classCache.put("getRealPath", clazz);
        classCache.put("getAttribute", clazz);
        classCache.put("log", clazz);
    }


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


    /**
     * Wrapped application context.
     */
    private ApplicationContext context = null;
    


    // ------------------------------------------------- ServletContext Methods


    public ServletContext getContext(String uripath) {
        ServletContext theContext = null;
        if (SecurityUtil.isPackageProtectionEnabled()) {
            theContext = (ServletContext)
                doPrivileged("getContext", new Object[]{uripath});
        } else {
            theContext = context.getContext(uripath);
        }
        if ((theContext != null) &&
            (theContext instanceof ApplicationContext)){
            theContext = ((ApplicationContext)theContext).getFacade();
        }
        return (theContext);
    }


    public int getMajorVersion() {
        return context.getMajorVersion();
    }


    public int getMinorVersion() {
        return context.getMinorVersion();
    }


    public String getMimeType(String file) {
        if (SecurityUtil.isPackageProtectionEnabled()) {
            return (String)doPrivileged("getMimeType", new Object[]{file});
        } else {
            return context.getMimeType(file);
        }
    }


    public Set getResourcePaths(String path) {
        if (SecurityUtil.isPackageProtectionEnabled()){
            return (Set)doPrivileged("getResourcePaths", new Object[]{path});
        } else {
            return context.getResourcePaths(path);
        }
    }


    public URL getResource(String path)
        throws MalformedURLException {
        if (Globals.IS_SECURITY_ENABLED) {
            try {
                return (URL) invokeMethod(context, "getResource", 
                                          new Object[]{path});
            } catch(Throwable t) {
                if (t instanceof MalformedURLException){
                    throw (MalformedURLException)t;
                }
                return null;
            }
        } else {
            return context.getResource(path);
        }
    }


    public InputStream getResourceAsStream(String path) {
        if (SecurityUtil.isPackageProtectionEnabled()) {
            return (InputStream) doPrivileged("getResourceAsStream", 
                                              new Object[]{path});
        } else {
            return context.getResourceAsStream(path);
        }
    }


    public RequestDispatcher getRequestDispatcher(final String path) {
        if (SecurityUtil.isPackageProtectionEnabled()) {
            return (RequestDispatcher) doPrivileged("getRequestDispatcher", 
                                                    new Object[]{path});
        } else {
            return context.getRequestDispatcher(path);
        }
    }


    public RequestDispatcher getNamedDispatcher(String name) {
        if (SecurityUtil.isPackageProtectionEnabled()) {
            return (RequestDispatcher) doPrivileged("getNamedDispatcher", 
                                                    new Object[]{name});
        } else {
            return context.getNamedDispatcher(name);
        }
    }


    public Servlet getServlet(String name)
        throws ServletException {
        if (SecurityUtil.isPackageProtectionEnabled()) {
            try {
                return (Servlet) invokeMethod(context, "getServlet", 
                                              new Object[]{name});
            } catch (Throwable t) {
                if (t instanceof ServletException) {
                    throw (ServletException) t;
                }
                return null;
            }
        } else {
            return context.getServlet(name);
        }
    }


    public Enumeration getServlets() {
        if (SecurityUtil.isPackageProtectionEnabled()) {
            return (Enumeration) doPrivileged("getServlets", null);
        } else {
            return context.getServlets();
        }
    }


    public Enumeration getServletNames() {
        if (SecurityUtil.isPackageProtectionEnabled()) {
            return (Enumeration) doPrivileged("getServletNames", null);
        } else {
            return context.getServletNames();
        }
   }


    public void log(String msg) {
        if (SecurityUtil.isPackageProtectionEnabled()) {
            doPrivileged("log", new Object[]{msg} );
        } else {
            context.log(msg);
        }
    }


    public void log(Exception exception, String msg) {