001/* 002 * Copyright 2002-2019 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.cglib.core; 018 019/** 020 * CGLIB GeneratorStrategy variant which exposes the application ClassLoader 021 * as current thread context ClassLoader for the time of class generation. 022 * The ASM ClassWriter in Spring's ASM variant will pick it up when doing 023 * common superclass resolution. 024 * 025 * @author Juergen Hoeller 026 * @since 5.2 027 */ 028public class ClassLoaderAwareGeneratorStrategy extends DefaultGeneratorStrategy { 029 030 private final ClassLoader classLoader; 031 032 public ClassLoaderAwareGeneratorStrategy(ClassLoader classLoader) { 033 this.classLoader = classLoader; 034 } 035 036 @Override 037 public byte[] generate(ClassGenerator cg) throws Exception { 038 if (this.classLoader == null) { 039 return super.generate(cg); 040 } 041 042 Thread currentThread = Thread.currentThread(); 043 ClassLoader threadContextClassLoader; 044 try { 045 threadContextClassLoader = currentThread.getContextClassLoader(); 046 } 047 catch (Throwable ex) { 048 // Cannot access thread context ClassLoader - falling back... 049 return super.generate(cg); 050 } 051 052 boolean overrideClassLoader = !this.classLoader.equals(threadContextClassLoader); 053 if (overrideClassLoader) { 054 currentThread.setContextClassLoader(this.classLoader); 055 } 056 try { 057 return super.generate(cg); 058 } 059 finally { 060 if (overrideClassLoader) { 061 // Reset original thread context ClassLoader. 062 currentThread.setContextClassLoader(threadContextClassLoader); 063 } 064 } 065 } 066 067}