Mercurial > hg > blitz_condensed
view src/com/go/trove/util/ClassInjector.java @ 0:3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
author | Dan Creswell <dan.creswell@gmail.com> |
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date | Sat, 21 Mar 2009 11:00:06 +0000 |
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/* ==================================================================== * Trove - Copyright (c) 1997-2000 Walt Disney Internet Group * ==================================================================== * The Tea Software License, Version 1.1 * * Copyright (c) 2000 Walt Disney Internet Group. 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 acknowledgment: * "This product includes software developed by the * Walt Disney Internet Group (http://opensource.go.com/)." * Alternately, this acknowledgment may appear in the software itself, * if and wherever such third-party acknowledgments normally appear. * * 4. The names "Tea", "TeaServlet", "Kettle", "Trove" and "BeanDoc" must * not be used to endorse or promote products derived from this * software without prior written permission. For written * permission, please contact opensource@dig.com. * * 5. Products derived from this software may not be called "Tea", * "TeaServlet", "Kettle" or "Trove", nor may "Tea", "TeaServlet", * "Kettle", "Trove" or "BeanDoc" appear in their name, without prior * written permission of the Walt Disney Internet 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 WALT DISNEY INTERNET GROUP 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. * ==================================================================== * * For more information about Tea, please see http://opensource.go.com/. */ package com.go.trove.util; import java.io.OutputStream; import java.io.ByteArrayOutputStream; import java.io.ByteArrayInputStream; import java.io.File; import java.io.InputStream; import java.io.FileInputStream; import java.io.IOException; import java.lang.ref.*; import java.net.URL; import java.net.URLConnection; import java.net.URLStreamHandler; import java.util.*; import java.util.zip.GZIPInputStream; import java.util.zip.GZIPOutputStream; /****************************************************************************** * A special ClassLoader that allows classes to be defined by directly * injecting the bytecode. All classes other than those injected are loaded * from the parent ClassLoader, which is the ClassLoader that loaded this * class. If a directory is passed in, the ClassInjector looks there for * non-injected class files before asking the parent ClassLoader for a class. * * @author Brian S O'Neill * @version * <!--$$Revision: 1.1 $-->, <!--$$JustDate:--> 7/30/01 <!-- $--> */ public class ClassInjector extends ClassLoader { private static Map cShared = new NullKeyMap(new IdentityMap()); /** * Returns a shared ClassInjector instance. */ public static ClassInjector getInstance() { return getInstance(null); } /** * Returns a shared ClassInjector instance for the given ClassLoader. */ public static ClassInjector getInstance(ClassLoader loader) { ClassInjector injector = null; synchronized (cShared) { Reference ref = (Reference)cShared.get(loader); if (ref != null) { injector = (ClassInjector)ref.get(); } if (injector == null) { injector = new ClassInjector(loader); cShared.put(loader, new WeakReference(injector)); } return injector; } } // Parent ClassLoader, used to load classes that aren't defined by this. private ClassLoader mSuperLoader; private File[] mRootClassDirs; private String mRootPackage; // A set of all the classes defined by the ClassInjector. private Map mDefined = Collections.synchronizedMap(new HashMap()); // A map to store raw bytecode for future use in getResourceAsStream(). private Map mGZippedBytecode; private URLStreamHandler mFaker; /** * Construct a ClassInjector that uses the ClassLoader that loaded this * class as a parent, and it has no root class directory or root package. */ public ClassInjector() { this(null, (File[])null, null); } /** * Construct a ClassInjector that has no root class directory or root * package. * * @param parent optional parent ClassLoader to default to when a class * cannot be loaded with this ClassInjector. */ public ClassInjector(ClassLoader parent) { this(parent, (File[])null, null); } /** * Construct a ClassInjector that uses the ClassLoader that loaded this * class as a parent. * * @param rootClassDir optional directory to look for non-injected classes * @param rootPackage optional package name for the root directory */ public ClassInjector(File rootClassDir, String rootPackage) { this(null, (rootClassDir == null) ? null : new File[]{rootClassDir}, rootPackage); } /** * @param parent optional parent ClassLoader to default to when a class * cannot be loaded with this ClassInjector. * @param rootClassDir optional directory to look for non-injected classes * @param rootPackage optional package name for the root directory */ public ClassInjector(ClassLoader parent, File rootClassDir, String rootPackage) { this(parent, (rootClassDir == null) ? null : new File[]{rootClassDir}, rootPackage); } /** * Construct a ClassInjector that uses the ClassLoader that loaded this * class as a parent. * * @param rootClassDirs optional directories to look for non-injected * classes * @param rootPackage optional package name for the root directory */ public ClassInjector(File[] rootClassDirs, String rootPackage) { this(null, rootClassDirs, rootPackage); } /** * @param parent optional parent ClassLoader to default to when a class * cannot be loaded with this ClassInjector. * @param rootClassDirs optional directories to look for non-injected * classes * @param rootPackage optional package name for the root directory */ public ClassInjector(ClassLoader parent, File[] rootClassDirs, String rootPackage) { this(parent, rootClassDirs, rootPackage, false); } /** * @param parent optional parent ClassLoader to default to when a class * cannot be loaded with this ClassInjector. * @param rootClassDirs optional directories to look for non-injected * classes * @param rootPackage optional package name for the root directory * @param keepRawBytecode if true, will cause the ClassInjector to store * the raw bytecode of defined classes. */ public ClassInjector(ClassLoader parent, File[] rootClassDirs, String rootPackage, boolean keepRawBytecode) { super(); if (parent == null) { parent = getClass().getClassLoader(); } mSuperLoader = parent; if (rootClassDirs != null) { mRootClassDirs = (File[])rootClassDirs.clone(); } if (rootPackage != null && !rootPackage.endsWith(".")) { rootPackage += '.'; } mRootPackage = rootPackage; if (keepRawBytecode) { mGZippedBytecode = Collections.synchronizedMap(new HashMap()); } } /** * Get a stream used to define a class. Close the stream to finish the * definition. * * @param the fully qualified name of the class to be defined. */ public OutputStream getStream(String name) { return new Stream(name); } public URL getResource(String name) { if (mGZippedBytecode != null) { if (mGZippedBytecode.containsKey(name)) { try { return new URL("file", null, -1, name, getURLFaker()); } catch (Exception e) { e.printStackTrace(); } System.out.println("created URL for " + name); } } return mSuperLoader.getResource(name); } private URLStreamHandler getURLFaker() { if (mFaker == null) { mFaker = new URLFaker(); } return mFaker; } protected Class loadClass(String name, boolean resolve) throws ClassNotFoundException { Class clazz = findLoadedClass(name); if (clazz == null) { synchronized (this) { clazz = findLoadedClass(name); if (clazz == null) { clazz = loadFromFile(name); if (clazz == null) { if (mSuperLoader != null) { clazz = mSuperLoader.loadClass(name); } else { clazz = findSystemClass(name); } if (clazz == null) { throw new ClassNotFoundException(name); } } } } } if (resolve) { resolveClass(clazz); } return clazz; } protected void define(String name, byte[] data) { defineClass(name, data, 0, data.length); if (mGZippedBytecode != null) { try { ByteArrayOutputStream baos = new ByteArrayOutputStream(); GZIPOutputStream gz = new GZIPOutputStream(baos); gz.write(data,0,data.length); gz.close(); mGZippedBytecode.put(name.replace('.','/') + ".class", baos.toByteArray()); } catch (IOException ioe) { ioe.printStackTrace(); } } } private Class loadFromFile(String name) throws ClassNotFoundException { if (mRootClassDirs == null) { return null; } String fileName = name; if (mRootPackage != null) { if (fileName.startsWith(mRootPackage)) { fileName = fileName.substring(mRootPackage.length()); } else { return null; } } fileName = fileName.replace('.', File.separatorChar); ClassNotFoundException error = null; for (int i=0; i<mRootClassDirs.length; i++) { File file = new File(mRootClassDirs[i], fileName + ".class"); if (file.exists()) { try { byte[] buffer = new byte[(int)file.length()]; int avail = buffer.length; int offset = 0; InputStream in = new FileInputStream(file); int len = -1; while ( (len = in.read(buffer, offset, avail)) > 0 ) { offset += len; if ( (avail -= len) <= 0 ) { avail = buffer.length; byte[] newBuffer = new byte[avail * 2]; System.arraycopy(buffer, 0, newBuffer, 0, avail); buffer = newBuffer; } } in.close(); return defineClass(name, buffer, 0, offset); } catch (IOException e) { if (error == null) { error = new ClassNotFoundException (fileName + ": " + e.toString()); } } } } if (error != null) { throw error; } else { return null; } } private class Stream extends ByteArrayOutputStream { private String mName; public Stream(String name) { super(1024); mName = name; } public void close() { synchronized (mDefined) { if (mDefined.get(mName) == null) { define(mName, toByteArray()); mDefined.put(mName, mName); } } } } private class URLFaker extends URLStreamHandler { protected URLConnection openConnection(URL u) throws IOException { return new ClassInjector.ResourceConnection(u); } } private class ResourceConnection extends URLConnection { String resourceName; public ResourceConnection(URL u) { super(u); resourceName = u.getFile(); } // not really needed here but it was abstract. public void connect() {} public InputStream getInputStream() throws IOException { try { if (mGZippedBytecode != null) { if (mGZippedBytecode.get(resourceName) != null) { return new GZIPInputStream(new ByteArrayInputStream ((byte[])mGZippedBytecode.get(resourceName))); } else { System.out.println(resourceName + " not found in bytecode map."); } } else { System.out.println("no bytecode map configured in "+ ClassInjector.this); } } catch (Exception e) { e.printStackTrace(); } return null; } } }