1 /* 2 * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.xml.internal.bind.v2.runtime.reflect.opt; 27 28 import java.io.InputStream; 29 import java.util.logging.Level; 30 import java.util.logging.Logger; 31 32 import com.sun.xml.internal.bind.Util; 33 import com.sun.xml.internal.bind.v2.bytecode.ClassTailor; 34 35 /** 36 * @author Kohsuke Kawaguchi 37 */ 38 class AccessorInjector { 39 40 private static final Logger logger = Util.getClassLogger(); 41 42 protected static final boolean noOptimize = 43 Util.getSystemProperty(ClassTailor.class.getName()+".noOptimize")!=null; 44 45 static { 46 if(noOptimize) 47 logger.info("The optimized code generation is disabled"); 48 } 49 50 /** 51 * Loads the optimized class and returns it. 52 * 53 * @return null 54 * if it fails for some reason. 55 */ 56 public static Class<?> prepare( 57 Class beanClass, String templateClassName, String newClassName, String... replacements ) { 58 59 if(noOptimize) 60 return null; 61 62 try { 63 ClassLoader cl = SecureLoader.getClassClassLoader(beanClass); 64 if(cl==null) return null; // how do I inject classes to this "null" class loader? for now, back off. 65 66 Class c = null; 67 synchronized (AccessorInjector.class) { 68 c = Injector.find(cl,newClassName); 69 if(c==null) { 70 byte[] image = tailor(templateClassName,newClassName,replacements); 71 // try { 72 // new FileOutputStream("debug.class").write(image); 73 // } catch (IOException e) { 74 // e.printStackTrace(); 75 // } 76 if(image==null) 77 return null; 78 c = Injector.inject(cl,newClassName,image); 79 } 80 } 81 return c; 82 } catch(SecurityException e) { 83 // we don't have enough permission to do this 84 logger.log(Level.INFO,"Unable to create an optimized TransducedAccessor ",e); 85 return null; 86 } 87 } 88 89 90 /** 91 * Customizes a class file by replacing constant pools. 92 * 93 * @param templateClassName 94 * The resource that contains the template class file. 95 * @param replacements 96 * A list of pair of strings that specify the substitution 97 * {@code String[]{search_0, replace_0, search_1, replace_1, ..., search_n, replace_n } 98 * 99 * The search strings found in the constant pool will be replaced by the corresponding 100 * replacement string. 101 */ 102 private static byte[] tailor( String templateClassName, String newClassName, String... replacements ) { 103 InputStream resource; 104 if(CLASS_LOADER!=null) 105 resource = CLASS_LOADER.getResourceAsStream(templateClassName+".class"); 106 else 107 resource = ClassLoader.getSystemResourceAsStream(templateClassName+".class"); 108 if(resource==null) 109 return null; 110 111 return ClassTailor.tailor(resource,templateClassName,newClassName,replacements); 112 } 113 114 private static final ClassLoader CLASS_LOADER = SecureLoader.getClassClassLoader(AccessorInjector.class); 115 }