/* * Copyright (c) 2001, 2008, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation.  Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */package sun.misc; import java.util.ArrayList; /** * This is an abstract base class which is called by java.lang.ClassLoader * when ClassFormatError is thrown inside defineClass(). * * The purpose of this class is to allow applications (e.g. Java Plug-in) * to have a chance to transform the byte code from one form to another * if necessary. * * One application of this class is used by Java Plug-in to transform * malformed JDK 1.1 class file into a well-formed Java 2 class file * on-the-fly, so JDK 1.1 applets with malformed class file in the * Internet may run in Java 2 after transformation. * * @author      Stanley Man-Kit Ho */ public abstract class ClassFileTransformer{    // Singleton of ClassFileTransformer    //    private static ArrayList<ClassFileTransformer> transformerList        = new ArrayList<ClassFileTransformer>();    private static ClassFileTransformer[] transformers        = new ClassFileTransformer[0];     /**     * Add the class file transformer object.     *     * @param t Class file transformer instance     */    public static void add(ClassFileTransformer t)    {        synchronized(transformerList)        {            transformerList.add(t);            transformers = transformerList.toArray(new ClassFileTransformer[0]);        }    }     /**     * Get the array of ClassFileTransformer object.     *     * @return ClassFileTransformer object array     */    public static ClassFileTransformer[] getTransformers()    {        // transformers is not intended to be changed frequently,        // so it is okay to not put synchronized block here        // to speed up performance.        //        return transformers;    }      /**     * Transform a byte array from one to the other.     *     * @param b Byte array     * @param off Offset     * @param len Length of byte array     * @return Transformed byte array     */    public abstract byte[] transform(byte[] b, int off, int len)                           throws ClassFormatError;}