Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ package org.codehaus.groovy.classgen; import groovy.lang.GroovyClassLoader; import org.apache.groovy.io.StringBuilderWriter; import org.codehaus.groovy.ast.ClassNode; import org.codehaus.groovy.ast.CompileUnit; import org.codehaus.groovy.control.CompilationUnit; import org.codehaus.groovy.control.CompilerConfiguration; import org.codehaus.groovy.control.SourceUnit; import org.objectweb.asm.ClassVisitor; import org.objectweb.asm.Opcodes; import org.objectweb.asm.util.ASMifier; import org.objectweb.asm.util.CheckClassAdapter; import org.objectweb.asm.util.TraceClassVisitor; import java.io.OutputStreamWriter; import java.io.PrintWriter; /** * A class loader used for debugging the bytecode generation. * This will log all bytecode being loaded */ public class DumpingClassLoader extends GroovyClassLoader implements Opcodes { protected static boolean CHECK_CLASS = false; protected static boolean DUMP_CLASS = true; public DumpingClassLoader(ClassLoader parentLoader) { super(parentLoader); } protected class DebugCollector extends ClassCollector { DebugCollector(GroovyClassLoader cl, CompilationUnit unit, SourceUnit su) { super(new GroovyClassLoader.InnerLoader(cl), unit, su); } public void call(ClassVisitor classWriter, ClassNode classNode) { // lets test out the class verifier if (DUMP_CLASS) { dumper.visitClass(classNode); } if (CHECK_CLASS) { checker.visitClass(classNode); } super.call(classWriter, classNode); } } protected ClassCollector createCollector(CompilationUnit unit) { return new DebugCollector(this, unit, null); } protected TraceClassVisitor dumpVisitor = new TraceClassVisitor(null, new ASMifier(), new PrintWriter(new OutputStreamWriter(System.out))); protected TraceClassVisitor invisibleDumpVisitor = new TraceClassVisitor(null, new ASMifier(), new PrintWriter(new StringBuilderWriter())); protected CompileUnit unit = new CompileUnit(this, new CompilerConfiguration()); protected ClassGenerator checker = new AsmClassGenerator(null, new GeneratorContext(unit), new CheckClassAdapter(invisibleDumpVisitor), null); protected ClassGenerator dumper = new AsmClassGenerator(null, new GeneratorContext(unit), dumpVisitor, null); }