ASF_20_SRC_AUTO/src/blocks/paranoid/java/org/apache/cocoon/servlet/ParanoidCocoonServlet.java - cocoon - Git at Google

 /*
  * 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.cocoon.servlet;

 import java.io.File;
 import java.io.FileReader;
 import java.io.FilenameFilter;
 import java.io.IOException;
 import java.io.LineNumberReader;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.ArrayList;
 import java.util.List;

 import javax.servlet.Servlet;
 import javax.servlet.ServletConfig;
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServlet;

 /**
  * This servlet builds a classloading sandbox and runs another servlet inside that
  * sandbox. The purpose is to shield the libraries and classes shipped with the web
  * application from any other classes with the same name that may exist in the system,
  * such as Xerces and Xalan versions included in JDK 1.4.
  * <p>
  * This servlet propagates all initialisation parameters to the sandboxed servlet, and
  * accepts the parameters <code>servlet-class</code> and <code>paranoid-classpath</code>.
  * <ul>
  *  <li><code>servlet-class</code> defines the sandboxed servlet class, the default is
  *      {@link CocoonServlet}
  *  <li><code>paranoid-classpath</code> expects the name of a text file that can contain
  *      lines begining with <code>class-dir:<code> (directory containing classes),
  *      <code>lib-dir:<code> (directory containing JAR or ZIP libraries) and <code>#</code>
  *      (for comments). <br/>
  *      All other lines are considered as URLs.
  *      <br/>
  *      It is also possible to use a the pseudo protocol prefix<code>context:/<code> which
  *      is resolved to the basedir of the servlet context.
  * </ul>
  *
  * @author <a href="mailto:bloritsch@apache.org">Berin Loritsch</a>
  * @author <a href="http://www.apache.org/~sylvain/">Sylvain Wallez</a>
  * @version CVS $Id: ParanoidCocoonServlet.java,v 1.3 2004/03/05 13:02:02 bdelacretaz Exp $
  */

 public class ParanoidCocoonServlet extends HttpServlet {

 	/**
 	 * The name of the actual servlet class.
 	 */
 	public static final String DEFAULT_SERVLET_CLASS = "org.apache.cocoon.servlet.CocoonServlet";

     protected static final String CONTEXT_PREFIX = "context:";

     protected static final String FILE_PREFIX = "file:";

 	protected Servlet servlet;

     protected ClassLoader classloader;

 	public void init(ServletConfig config) throws ServletException {

 		super.init(config);

 		// Create the classloader in which we will load the servlet
         // this can either be specified by an external file configured
         // as a parameter in web.xml or (the default) all jars and
         // classes from WEB-INF/lib and WEB-INF/classes are used.
         final String externalClasspath = config.getInitParameter("paranoid-classpath");
         if ( externalClasspath == null ) {
             this.classloader = this.getClassLoader(this.getContextDir());
         } else {
             this.classloader = this.getClassLoader(externalClasspath, this.getContextDir());
         }

         String servletName = config.getInitParameter("servlet-class");
         if (servletName == null) {
             servletName = DEFAULT_SERVLET_CLASS;
         }

         // Create the servlet
 		try {
 			Class servletClass = this.classloader.loadClass(servletName);

 			this.servlet = (Servlet)servletClass.newInstance();

 		} catch(Exception e) {
 			throw new ServletException("Cannot load servlet " + servletName, e);
 		}

 		// Always set the context classloader. JAXP uses it to find a ParserFactory,
 		// and thus fails if it's not set to the webapp classloader.
         final ClassLoader old = Thread.currentThread().getContextClassLoader();
         try {
             Thread.currentThread().setContextClassLoader(this.classloader);

             // Inlitialize the actual servlet
             this.initServlet();
         } finally {
             Thread.currentThread().setContextClassLoader(old);
         }

 	}

 	/**
 	 * Initialize the wrapped servlet. Subclasses (see {@link BootstrapServlet} change the
 	 * <code>ServletConfig</code> given to the servlet.
 	 *
 	 * @throws ServletException
 	 */
 	protected void initServlet() throws ServletException {
 		this.servlet.init(this.getServletConfig());
 	}

 	/**
 	 * Get the web application context directory.
 	 *
 	 * @return the context dir
 	 * @throws ServletException
 	 */
 	protected File getContextDir() throws ServletException {
 		String result = getServletContext().getRealPath("/");
 		if (result == null) {
 			throw new ServletException(this.getClass().getName() + " cannot run in an undeployed WAR file");
 		}
 		return new File(result);
 	}

 	/**
 	 * Get the classloader that will be used to create the actual servlet. Its classpath is defined
 	 * by the WEB-INF/classes and WEB-INF/lib directories in the context dir.
 	 */
 	protected ClassLoader getClassLoader(File contextDir) throws ServletException {
 		List urlList = new ArrayList();

 		try {
 			File classDir = new File(contextDir + "/WEB-INF/classes");
 			if (classDir.exists()) {
 				if (!classDir.isDirectory()) {
 					throw new ServletException(classDir + " exists but is not a directory");
 				}

 				URL classURL = classDir.toURL();
 				log("Adding class directory " + classURL);
 				urlList.add(classURL);

 			}

             // List all .jar and .zip
 			File libDir = new File(contextDir + "/WEB-INF/lib");
 			File[] libraries = libDir.listFiles(new JarFileFilter());

 			for (int i = 0; i < libraries.length; i++) {
 				URL lib = libraries[i].toURL();
 				log("Adding class library " + lib);
 				urlList.add(lib);
 			}
 		} catch (MalformedURLException mue) {
 			throw new ServletException(mue);
 		}

 		URL[] urls = (URL[])urlList.toArray(new URL[urlList.size()]);

 		return ParanoidClassLoader.newInstance(urls, this.getClass().getClassLoader());
 	}

     /**
      * Get the classloader that will be used to create the actual servlet. Its classpath is defined
      * by an external file.
      */
     protected ClassLoader getClassLoader(String externalClasspath, File contextDir)
     throws ServletException {
         final List urlList = new ArrayList();

         log("Adding classpath from " + externalClasspath);
         try {
             FileReader fileReader = new FileReader(externalClasspath);
             LineNumberReader lineReader = new LineNumberReader(fileReader);

             String line;
             do {
                 line = lineReader.readLine();
                 if ( line != null ) {
                     if (line.startsWith("class-dir:")) {
                         line = line.substring("class-dir:".length()).trim();
                         if( line.startsWith(CONTEXT_PREFIX)) {
                             line = contextDir + line.substring(CONTEXT_PREFIX.length());
                         }
                         URL url = new File(line).toURL();
                         log("Adding class directory " + url);
                         urlList.add(url);

                     } else if (line.startsWith("lib-dir:")) {
                         line = line.substring("lib-dir:".length()).trim();
                         if( line.startsWith(CONTEXT_PREFIX)) {
                             line = contextDir + line.substring(CONTEXT_PREFIX.length());
                         }
                         File dir = new File(line);
                         File[] libraries = dir.listFiles(new JarFileFilter());
                         log("Adding " + libraries.length + " libraries from " + dir.toURL());
                         for (int i = 0; i < libraries.length; i++) {
                             URL url = libraries[i].toURL();
                             urlList.add(url);
                         }
                     } else if(line.startsWith("#")) {
                         // skip it (consider it as comment)
                     } else {
                         // Consider it as a URL
                         final URL lib;
                         if( line.startsWith(CONTEXT_PREFIX)) {
                             line = FILE_PREFIX + "/" + contextDir +
                                 line.substring(CONTEXT_PREFIX.length()).trim();
                         }
                         if ( line.indexOf(':') == -1) {
                             File entry = new File(line);
                             lib = entry.toURL();
                         } else {
                             lib = new URL(line);
                         }
                         log("Adding class URL " + lib);
                         urlList.add(lib);
                     }
                 }
             } while ( line != null );
             lineReader.close();
         } catch (IOException io) {
             throw new ServletException(io);
         }

         URL[] urls = (URL[])urlList.toArray(new URL[urlList.size()]);

         return ParanoidClassLoader.newInstance(urls, this.getClass().getClassLoader());
     }

 	/**
 	 * Service the request by delegating the call to the real servlet
 	 */
 	public void service(ServletRequest request, ServletResponse response)
     throws ServletException, IOException {

         final ClassLoader old = Thread.currentThread().getContextClassLoader();
         try {
 		    Thread.currentThread().setContextClassLoader(this.classloader);
 		    this.servlet.service(request, response);
         } finally {
             Thread.currentThread().setContextClassLoader(old);
         }
 	}

 	/**
 	 * Destroy the actual servlet
 	 */
 	public void destroy() {

         if ( this.servlet != null ) {
             final ClassLoader old = Thread.currentThread().getContextClassLoader();
             try {
                 Thread.currentThread().setContextClassLoader(this.classloader);
                 this.servlet.destroy();
             } finally {
                 Thread.currentThread().setContextClassLoader(old);
             }
         }

 		super.destroy();
 	}

     private class JarFileFilter implements FilenameFilter {
         public boolean accept(File dir, String name) {
             return name.endsWith(".zip") || name.endsWith(".jar");
         }
     }

 }
	/*
	* 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.cocoon.servlet;

	import java.io.File;
	import java.io.FileReader;
	import java.io.FilenameFilter;
	import java.io.IOException;
	import java.io.LineNumberReader;
	import java.net.MalformedURLException;
	import java.net.URL;
	import java.util.ArrayList;
	import java.util.List;

	import javax.servlet.Servlet;
	import javax.servlet.ServletConfig;
	import javax.servlet.ServletException;
	import javax.servlet.ServletRequest;
	import javax.servlet.ServletResponse;
	import javax.servlet.http.HttpServlet;

	/**
	* This servlet builds a classloading sandbox and runs another servlet inside that
	* sandbox. The purpose is to shield the libraries and classes shipped with the web
	* application from any other classes with the same name that may exist in the system,
	* such as Xerces and Xalan versions included in JDK 1.4.
	* <p>
	* This servlet propagates all initialisation parameters to the sandboxed servlet, and
	* accepts the parameters <code>servlet-class</code> and <code>paranoid-classpath</code>.
	* <ul>
	* <li><code>servlet-class</code> defines the sandboxed servlet class, the default is
	* {@link CocoonServlet}
	* <li><code>paranoid-classpath</code> expects the name of a text file that can contain
	* lines begining with <code>class-dir:<code> (directory containing classes),
	* <code>lib-dir:<code> (directory containing JAR or ZIP libraries) and <code>#</code>
	* (for comments). <br/>
	* All other lines are considered as URLs.
	* <br/>
	* It is also possible to use a the pseudo protocol prefix<code>context:/<code> which
	* is resolved to the basedir of the servlet context.
	* </ul>
	*
	* @author <a href="mailto:bloritsch@apache.org">Berin Loritsch</a>
	* @author <a href="http://www.apache.org/~sylvain/">Sylvain Wallez</a>
	* @version CVS $Id: ParanoidCocoonServlet.java,v 1.3 2004/03/05 13:02:02 bdelacretaz Exp $
	*/

	public class ParanoidCocoonServlet extends HttpServlet {

	/**
	* The name of the actual servlet class.
	*/
	public static final String DEFAULT_SERVLET_CLASS = "org.apache.cocoon.servlet.CocoonServlet";

	protected static final String CONTEXT_PREFIX = "context:";

	protected static final String FILE_PREFIX = "file:";

	protected Servlet servlet;

	protected ClassLoader classloader;

	public void init(ServletConfig config) throws ServletException {

	super.init(config);

	// Create the classloader in which we will load the servlet
	// this can either be specified by an external file configured
	// as a parameter in web.xml or (the default) all jars and
	// classes from WEB-INF/lib and WEB-INF/classes are used.
	final String externalClasspath = config.getInitParameter("paranoid-classpath");
	if ( externalClasspath == null ) {
	this.classloader = this.getClassLoader(this.getContextDir());
	} else {
	this.classloader = this.getClassLoader(externalClasspath, this.getContextDir());
	}

	String servletName = config.getInitParameter("servlet-class");
	if (servletName == null) {
	servletName = DEFAULT_SERVLET_CLASS;
	}

	// Create the servlet
	try {
	Class servletClass = this.classloader.loadClass(servletName);

	this.servlet = (Servlet)servletClass.newInstance();

	} catch(Exception e) {
	throw new ServletException("Cannot load servlet " + servletName, e);
	}

	// Always set the context classloader. JAXP uses it to find a ParserFactory,
	// and thus fails if it's not set to the webapp classloader.
	final ClassLoader old = Thread.currentThread().getContextClassLoader();
	try {
	Thread.currentThread().setContextClassLoader(this.classloader);

	// Inlitialize the actual servlet
	this.initServlet();
	} finally {
	Thread.currentThread().setContextClassLoader(old);
	}

	}

	/**
	* Initialize the wrapped servlet. Subclasses (see {@link BootstrapServlet} change the
	* <code>ServletConfig</code> given to the servlet.
	*
	* @throws ServletException
	*/
	protected void initServlet() throws ServletException {
	this.servlet.init(this.getServletConfig());
	}

	/**
	* Get the web application context directory.
	*
	* @return the context dir
	* @throws ServletException
	*/
	protected File getContextDir() throws ServletException {
	String result = getServletContext().getRealPath("/");
	if (result == null) {
	throw new ServletException(this.getClass().getName() + " cannot run in an undeployed WAR file");
	}
	return new File(result);
	}

	/**
	* Get the classloader that will be used to create the actual servlet. Its classpath is defined
	* by the WEB-INF/classes and WEB-INF/lib directories in the context dir.
	*/
	protected ClassLoader getClassLoader(File contextDir) throws ServletException {
	List urlList = new ArrayList();

	try {
	File classDir = new File(contextDir + "/WEB-INF/classes");
	if (classDir.exists()) {
	if (!classDir.isDirectory()) {
	throw new ServletException(classDir + " exists but is not a directory");
	}

	URL classURL = classDir.toURL();
	log("Adding class directory " + classURL);
	urlList.add(classURL);

	}

	// List all .jar and .zip
	File libDir = new File(contextDir + "/WEB-INF/lib");
	File[] libraries = libDir.listFiles(new JarFileFilter());

	for (int i = 0; i < libraries.length; i++) {
	URL lib = libraries[i].toURL();
	log("Adding class library " + lib);
	urlList.add(lib);
	}
	} catch (MalformedURLException mue) {
	throw new ServletException(mue);
	}

	URL[] urls = (URL[])urlList.toArray(new URL[urlList.size()]);

	return ParanoidClassLoader.newInstance(urls, this.getClass().getClassLoader());
	}

	/**
	* Get the classloader that will be used to create the actual servlet. Its classpath is defined
	* by an external file.
	*/
	protected ClassLoader getClassLoader(String externalClasspath, File contextDir)
	throws ServletException {
	final List urlList = new ArrayList();

	log("Adding classpath from " + externalClasspath);
	try {
	FileReader fileReader = new FileReader(externalClasspath);
	LineNumberReader lineReader = new LineNumberReader(fileReader);

	String line;
	do {
	line = lineReader.readLine();
	if ( line != null ) {
	if (line.startsWith("class-dir:")) {
	line = line.substring("class-dir:".length()).trim();
	if( line.startsWith(CONTEXT_PREFIX)) {
	line = contextDir + line.substring(CONTEXT_PREFIX.length());
	}
	URL url = new File(line).toURL();
	log("Adding class directory " + url);
	urlList.add(url);

	} else if (line.startsWith("lib-dir:")) {
	line = line.substring("lib-dir:".length()).trim();
	if( line.startsWith(CONTEXT_PREFIX)) {
	line = contextDir + line.substring(CONTEXT_PREFIX.length());
	}
	File dir = new File(line);
	File[] libraries = dir.listFiles(new JarFileFilter());
	log("Adding " + libraries.length + " libraries from " + dir.toURL());
	for (int i = 0; i < libraries.length; i++) {
	URL url = libraries[i].toURL();
	urlList.add(url);
	}
	} else if(line.startsWith("#")) {
	// skip it (consider it as comment)
	} else {
	// Consider it as a URL
	final URL lib;
	if( line.startsWith(CONTEXT_PREFIX)) {
	line = FILE_PREFIX + "/" + contextDir +
	line.substring(CONTEXT_PREFIX.length()).trim();
	}
	if ( line.indexOf(':') == -1) {
	File entry = new File(line);
	lib = entry.toURL();
	} else {
	lib = new URL(line);
	}
	log("Adding class URL " + lib);
	urlList.add(lib);
	}
	}
	} while ( line != null );
	lineReader.close();
	} catch (IOException io) {
	throw new ServletException(io);
	}

	URL[] urls = (URL[])urlList.toArray(new URL[urlList.size()]);

	return ParanoidClassLoader.newInstance(urls, this.getClass().getClassLoader());
	}

	/**
	* Service the request by delegating the call to the real servlet
	*/
	public void service(ServletRequest request, ServletResponse response)
	throws ServletException, IOException {

	final ClassLoader old = Thread.currentThread().getContextClassLoader();
	try {
	Thread.currentThread().setContextClassLoader(this.classloader);
	this.servlet.service(request, response);
	} finally {
	Thread.currentThread().setContextClassLoader(old);
	}
	}

	/**
	* Destroy the actual servlet
	*/
	public void destroy() {

	if ( this.servlet != null ) {
	final ClassLoader old = Thread.currentThread().getContextClassLoader();
	try {
	Thread.currentThread().setContextClassLoader(this.classloader);
	this.servlet.destroy();
	} finally {
	Thread.currentThread().setContextClassLoader(old);
	}
	}

	super.destroy();
	}

	private class JarFileFilter implements FilenameFilter {
	public boolean accept(File dir, String name) {
	return name.endsWith(".zip") \|\| name.endsWith(".jar");
	}
	}

	}