Java tutorial
/* * Copyright 2010-2012 VMware and contributors * * Licensed 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.springsource.loaded.test.infra; import java.io.File; import java.io.FileInputStream; import java.io.PrintStream; import org.objectweb.asm.AnnotationVisitor; import org.objectweb.asm.Attribute; import org.objectweb.asm.ClassReader; import org.objectweb.asm.ClassVisitor; import org.objectweb.asm.FieldVisitor; import org.objectweb.asm.MethodVisitor; import org.objectweb.asm.Opcodes; import org.springsource.loaded.Utils; /** * @author Andy Clement */ public class ClassPrinter extends ClassVisitor implements Opcodes { private PrintStream destination; private boolean includeBytecode; private int includeFlags = 0x0000; public final static int INCLUDE_BYTECODE = 0x0001; public final static int INCLUDE_LINE_NUMBERS = 0x0002; public static void main(String[] argv) throws Exception { ClassReader reader = new ClassReader(Utils.loadBytesFromStream(new FileInputStream(new File(argv[0])))); reader.accept(new ClassPrinter(System.out, INCLUDE_BYTECODE), 0); } public ClassPrinter(PrintStream destination) { this(destination, INCLUDE_BYTECODE); } public ClassPrinter(PrintStream destination, int includeFlags) { super(ASM5); this.destination = destination; this.includeFlags = includeFlags; } public static void print(String message, byte[] bytes) { System.out.println(message); print(bytes, true); } public static void print(byte[] bytes) { print(bytes, true); } public static void print(byte[] bytes, int includeFlags) { ClassReader reader = new ClassReader(bytes); reader.accept(new ClassPrinter(System.out, includeFlags), 0); } public static void print(byte[] bytes, boolean includeBytecode) { ClassReader reader = new ClassReader(bytes); reader.accept(new ClassPrinter(System.out, includeBytecode ? INCLUDE_BYTECODE : 0), 0); } public static void print(PrintStream printStream, byte[] bytes, boolean includeBytecode) { ClassReader reader = new ClassReader(bytes); reader.accept(new ClassPrinter(printStream, includeBytecode ? INCLUDE_BYTECODE : 0), 0); } public static void print(String message, byte[] bytes, boolean includeBytecode) { System.out.println(message); print(bytes, includeBytecode); } public void visit(int version, int access, String name, String signature, String superName, String[] interfaces) { destination.println("CLASS: " + name + " v" + Integer.toString(version) + " " + toHex(access, 4) + "(" + toAccessForClass(access) + ") super " + superName + (interfaces == null || interfaces.length == 0 ? "" : " interfaces" + toString(interfaces))); } private String toString(Object[] os) { if (os == null) { return ""; } StringBuilder sb = new StringBuilder(); for (Object o : os) { sb.append(o).append(" "); } return sb.toString(); } private String toAccessForClass(int flags) { StringBuilder sb = new StringBuilder(); if ((flags & Opcodes.ACC_PUBLIC) != 0) { sb.append("public "); } if ((flags & Opcodes.ACC_PRIVATE) != 0) { sb.append("private "); } if ((flags & Opcodes.ACC_PROTECTED) != 0) { sb.append("protected "); } if ((flags & Opcodes.ACC_STATIC) != 0) { sb.append("static "); } if ((flags & Opcodes.ACC_FINAL) != 0) { sb.append("final "); } if ((flags & Opcodes.ACC_SYNCHRONIZED) != 0) { sb.append("synchronized "); } if ((flags & Opcodes.ACC_BRIDGE) != 0) { sb.append("bridge "); } if ((flags & Opcodes.ACC_VARARGS) != 0) { sb.append("varargs "); } if ((flags & Opcodes.ACC_NATIVE) != 0) { sb.append("native "); } if ((flags & Opcodes.ACC_ABSTRACT) != 0) { sb.append("abstract "); } if ((flags & Opcodes.ACC_SYNTHETIC) != 0) { sb.append("synthetic "); } if ((flags & Opcodes.ACC_DEPRECATED) != 0) { sb.append("deprecated "); } if ((flags & Opcodes.ACC_INTERFACE) != 0) { sb.append("interface "); } return sb.toString().trim(); } public static String toAccessForMember(int flags) { StringBuilder sb = new StringBuilder(); if ((flags & Opcodes.ACC_PUBLIC) != 0) { sb.append("public "); } if ((flags & Opcodes.ACC_PRIVATE) != 0) { sb.append("private "); } if ((flags & Opcodes.ACC_STATIC) != 0) { sb.append("static "); } if ((flags & Opcodes.ACC_PROTECTED) != 0) { sb.append("protected "); } if ((flags & Opcodes.ACC_FINAL) != 0) { sb.append("final "); } if ((flags & Opcodes.ACC_SUPER) != 0) { sb.append("super "); } if ((flags & Opcodes.ACC_INTERFACE) != 0) { sb.append("interface "); } if ((flags & Opcodes.ACC_ABSTRACT) != 0) { sb.append("abstract "); } if ((flags & Opcodes.ACC_SYNTHETIC) != 0) { sb.append("synthetic "); } if ((flags & Opcodes.ACC_ANNOTATION) != 0) { sb.append("annotation "); } if ((flags & Opcodes.ACC_ENUM) != 0) { sb.append("enum "); } if ((flags & Opcodes.ACC_DEPRECATED) != 0) { sb.append("deprecated "); } return sb.toString().trim(); } private String toHex(int i, int len) { StringBuilder sb = new StringBuilder("00000000"); sb.append(Integer.toHexString(i)); return "0x" + sb.substring(sb.length() - len); } public AnnotationVisitor visitAnnotation(String desc, boolean visible) { destination.print("ANNOTATION " + desc + " vis?" + visible + " VALUE "); return new AnnotationVisitorPrinter(); } class AnnotationVisitorPrinter extends AnnotationVisitor { public AnnotationVisitorPrinter() { super(ASM5); } public void visit(String name, Object value) { destination.print(name + "=" + value + " "); } public void visitEnum(String name, String desc, String value) { destination.print(name + "=" + desc + "." + value + " "); } public AnnotationVisitor visitAnnotation(String name, String desc) { destination.print(name + "=" + desc + " "); return new AnnotationVisitorPrinter(); } public AnnotationVisitor visitArray(String name) { destination.print(name + " "); return new AnnotationVisitorPrinter(); } public void visitEnd() { destination.println(); } } public void visitAttribute(Attribute attr) { } public void visitEnd() { destination.println(); } public FieldVisitor visitField(int access, String name, String desc, String signature, Object value) { StringBuilder sb = new StringBuilder(); sb.append("FIELD " + toHex(access, 4) + "(" + toAccessForMember(access) + ") " + name + " " + desc + (signature != null ? " " + signature : "")); destination.println(sb.toString().trim()); return null; } public void visitInnerClass(String name, String outerName, String innerName, int access) { destination.println("INNERCLASS: " + name + " " + outerName + " " + innerName + " " + access); } public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) { StringBuilder s = new StringBuilder(); s.append("METHOD: " + toHex(access, 4) + "(" + toAccessForMember(access) + ") " + name + desc + " " + fromArray(exceptions)); destination.println(s.toString().trim()); return (includeFlags & INCLUDE_BYTECODE) != 0 ? new MethodPrinter(destination, includeFlags) : null; } private String fromArray(Object[] os) { if (os == null) { return ""; } StringBuilder sb = new StringBuilder(); for (Object o : os) { sb.append(o).append(" "); } return sb.toString(); } public void visitOuterClass(String owner, String name, String desc) { destination.println("OUTERCLASS: " + owner + " " + name + " " + desc); } public void visitSource(String source, String debug) { destination.println("SOURCE: " + source + " " + debug); } }