Java tutorial
/* * $Header: /home/cvs/jakarta-tomcat-catalina/catalina/src/share/org/apache/catalina/util/ExtensionValidator.java,v 1.8 2003/09/02 21:22:06 remm Exp $ * $Revision: 1.8 $ * $Date: 2003/09/02 21:22:06 $ * * ==================================================================== * * The Apache Software License, Version 1.1 * * Copyright (c) 1999 The Apache Software Foundation. All rights * reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The end-user documentation included with the redistribution, if * any, must include the following acknowlegement: * "This product includes software developed by the * Apache Software Foundation (http://www.apache.org/)." * Alternately, this acknowlegement may appear in the software itself, * if and wherever such third-party acknowlegements normally appear. * * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software * Foundation" must not be used to endorse or promote products derived * from this software without prior written permission. For written * permission, please contact apache@apache.org. * * 5. Products derived from this software may not be called "Apache" * nor may "Apache" appear in their names without prior written * permission of the Apache Group. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * * [Additional notices, if required by prior licensing conditions] * */ package org.apache.catalina.util; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.util.ArrayList; import java.util.HashMap; import java.util.Iterator; import java.util.NoSuchElementException; import java.util.ResourceBundle; import java.util.StringTokenizer; import java.util.jar.JarInputStream; import java.util.jar.Manifest; import javax.naming.Binding; import javax.naming.NamingEnumeration; import javax.naming.NamingException; import javax.naming.directory.DirContext; import org.apache.catalina.core.StandardContext; import org.apache.naming.resources.Resource; /** * Ensures that all extension dependies are resolved for a WEB application * are met. This class builds a master list of extensions available to an * applicaiton and then validates those extensions. * * See http://java.sun.com/j2se/1.4/docs/guide/extensions/spec.html for * a detailed explanation of the extension mechanism in Java. * * @author Greg Murray * @author Justyna Horwat * @version $Revision: 1.8 $ $Date: 2003/09/02 21:22:06 $ * */ public final class ExtensionValidator { private static org.apache.commons.logging.Log log = org.apache.commons.logging.LogFactory .getLog(ExtensionValidator.class); /** * The string resources for this package. */ private static StringManager sm = StringManager.getManager("org.apache.catalina.util"); private static ExtensionValidator validator = null; private static HashMap containerAvailableExtensions = null; private static ArrayList containerManifestResources = null; private static ResourceBundle messages = null; // ----------------------------------------------------------- Constructors /** * Access to this class can only be made through the factory method * getInstance() * * This private constructor loads the container level extensions that are * available to all web applications. This method scans all extension * directories available via the "java.ext.dirs" System property. * * The System Class-Path is also scanned for jar files that may contain * available extensions. The system extensions are loaded only the * first time an instance of the ExtensionValidator is created. */ private ExtensionValidator() throws IOException { // check for container level optional packages String systemClasspath = System.getProperty("java.class.path"); StringTokenizer strTok = new StringTokenizer(systemClasspath, File.pathSeparator); // build a list of jar files in the classpath while (strTok.hasMoreTokens()) { String classpathItem = strTok.nextToken(); if (classpathItem.toLowerCase().endsWith(".jar")) { File item = new File(classpathItem); if (item.exists()) { addSystemResource(item); } } } // get the files in the extensions directory String extensionsDir = System.getProperty("java.ext.dirs"); if (extensionsDir != null) { StringTokenizer extensionsTok = new StringTokenizer(extensionsDir, File.pathSeparator); while (extensionsTok.hasMoreTokens()) { File targetDir = new File(extensionsTok.nextToken()); if (!targetDir.exists() || !targetDir.isDirectory()) { continue; } File[] files = targetDir.listFiles(); for (int i = 0; i < files.length; i++) { if (files[i].getName().toLowerCase().endsWith(".jar")) { addSystemResource(files[i]); } } } } } // --------------------------------------------------------- Public Methods /** * Runtime validation of a Web Applicaiton. * * This method uses JNDI to look up the resources located under a * <code>DirContext</code>. It locates Web Application MANIFEST.MF * file in the /META-INF/ directory of the application and all * MANIFEST.MF files in each JAR file located in the WEB-INF/lib * directory and creates an <code>ArrayList</code> of * <code>ManifestResorce<code> objects. These objects are then passed * to the validateManifestResources method for validation. * * @param dirContext The JNDI root of the Web Application * @param context The context from which the Logger and path to the * application * * @return true if all required extensions satisfied */ public static synchronized boolean validateApplication(DirContext dirContext, StandardContext context) throws IOException { String appName = context.getPath(); ArrayList appManifestResources = new ArrayList(); ManifestResource appManifestResource = null; // If the application context is null it does not exist and // therefore is not valid if (dirContext == null) return false; // Find the Manifest for the Web Applicaiton InputStream inputStream = null; try { NamingEnumeration wne = dirContext.listBindings("/META-INF/"); Binding binding = (Binding) wne.nextElement(); if (binding.getName().toUpperCase().equals("MANIFEST.MF")) { Resource resource = (Resource) dirContext.lookup("/META-INF/" + binding.getName()); inputStream = resource.streamContent(); Manifest manifest = new Manifest(inputStream); inputStream.close(); inputStream = null; ManifestResource mre = new ManifestResource( sm.getString("extensionValidator.web-application-manifest"), manifest, ManifestResource.WAR); appManifestResources.add(mre); } } catch (NamingException nex) { // Application does not contain a MANIFEST.MF file } catch (NoSuchElementException nse) { // Application does not contain a MANIFEST.MF file } finally { if (inputStream != null) { try { inputStream.close(); } catch (Throwable t) { // Ignore } } } // Locate the Manifests for all bundled JARs NamingEnumeration ne = null; try { if (dirContext != null) { ne = dirContext.listBindings("WEB-INF/lib/"); } while ((ne != null) && ne.hasMoreElements()) { Binding binding = (Binding) ne.nextElement(); if (!binding.getName().toLowerCase().endsWith(".jar")) { continue; } Resource resource = (Resource) dirContext.lookup("/WEB-INF/lib/" + binding.getName()); Manifest jmanifest = getManifest(resource.streamContent()); if (jmanifest != null) { ManifestResource mre = new ManifestResource(binding.getName(), jmanifest, ManifestResource.APPLICATION); appManifestResources.add(mre); } } } catch (NamingException nex) { // Jump out of the check for this application because it // has no resources } return validateManifestResources(appName, appManifestResources); } /** * Return an instance of the ExtensionValidator. * The ExtensionValidator is a singleton. */ public static ExtensionValidator getInstance() throws IOException { if (validator == null) { validator = new ExtensionValidator(); } return validator; } // -------------------------------------------------------- Private Methods /** * Validates a <code>ArrayList</code> of <code>ManifestResource</code> * objects. This method requires an application name (which is the * context root of the application at runtime). * * <code>false</false> is returned if the extension dependencies * represented by any given <code>ManifestResource</code> objects * is not met. * * This method should also provide static validation of a Web Applicaiton * if provided with the necessary parameters. * * @param appName The name of the Application that will appear in the * error messages * @param resources A list of <code>ManifestResource</code> objects * to be validated. * * @return true if manifest resource file requirements are met */ private static boolean validateManifestResources(String appName, ArrayList resources) { boolean passes = true; int failureCount = 0; HashMap availableExtensions = null; Iterator it = resources.iterator(); while (it.hasNext()) { ManifestResource mre = (ManifestResource) it.next(); ArrayList requiredList = mre.getRequiredExtensions(); if (requiredList == null) { continue; } // build the list of available extensions if necessary if (availableExtensions == null) { availableExtensions = buildAvailableExtensionsMap(resources); } // load the container level resource map if it has not been built // yet if (containerAvailableExtensions == null) { containerAvailableExtensions = buildAvailableExtensionsMap(containerManifestResources); } // iterate through the list of required extensions Iterator rit = requiredList.iterator(); while (rit.hasNext()) { Extension requiredExt = (Extension) rit.next(); String extId = requiredExt.getUniqueId(); // check the applicaion itself for the extension if (availableExtensions != null && availableExtensions.containsKey(extId)) { Extension targetExt = (Extension) availableExtensions.get(extId); if (targetExt.isCompatibleWith(requiredExt)) { requiredExt.setFulfilled(true); } // check the container level list for the extension } else if (containerAvailableExtensions != null && containerAvailableExtensions.containsKey(extId)) { Extension targetExt = (Extension) containerAvailableExtensions.get(extId); if (targetExt.isCompatibleWith(requiredExt)) { requiredExt.setFulfilled(true); } } else { // Failure log.info(sm.getString("extensionValidator.extension-not-found-error", appName, mre.getResourceName(), requiredExt.getExtensionName())); passes = false; failureCount++; } } } if (!passes) { log.info(sm.getString("extensionValidator.extension-validation-error", appName, failureCount + "")); } return passes; } /* * Build this list of available extensions so that we do not have to * re-build this list every time we iterate through the list of required * extensions. All available extensions in all of the * <code>MainfestResource</code> objects will be added to a * <code>HashMap</code> which is returned on the first dependency list * processing pass. * * The key is the name + implementation version. * * NOTE: A list is built only if there is a dependency that needs * to be checked (performance optimization). * * @param resources A list of <code>ManifestResource</code> objects * * @return HashMap Map of available extensions */ private static HashMap buildAvailableExtensionsMap(ArrayList resources) { HashMap availableMap = null; Iterator it = resources.iterator(); while (it.hasNext()) { ManifestResource mre = (ManifestResource) it.next(); HashMap map = mre.getAvailableExtensions(); if (map != null) { Iterator values = map.values().iterator(); while (values.hasNext()) { Extension ext = (Extension) values.next(); if (availableMap == null) { availableMap = new HashMap(); availableMap.put(ext.getUniqueId(), ext); } else if (!availableMap.containsKey(ext.getUniqueId())) { availableMap.put(ext.getUniqueId(), ext); } } } } return availableMap; } /** * Return the Manifest from a jar file or war file * * @param inStream Input stream to a WAR or JAR file * @return The WAR's or JAR's manifest */ private static Manifest getManifest(InputStream inStream) throws IOException { Manifest manifest = null; JarInputStream jin = null; try { jin = new JarInputStream(inStream); manifest = jin.getManifest(); jin.close(); jin = null; } finally { if (jin != null) { try { jin.close(); } catch (Throwable t) { // Ignore } } } return manifest; } /* * Checks to see if the given system JAR file contains a MANIFEST, and adds * it to the container's manifest resources. * * @param jarFile The system JAR whose manifest to add */ private static void addSystemResource(File jarFile) throws IOException { Manifest manifest = getManifest(new FileInputStream(jarFile)); if (manifest != null) { ManifestResource mre = new ManifestResource(jarFile.getAbsolutePath(), manifest, ManifestResource.SYSTEM); if (containerManifestResources == null) { containerManifestResources = new ArrayList(); } containerManifestResources.add(mre); } } }