| /*** |
| * ASM examples: examples showing how ASM can be used |
| * Copyright (c) 2000-2011 INRIA, France Telecom |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * 3. Neither the name of the copyright holders nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF |
| * THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| import java.io.FileOutputStream; |
| import java.io.PrintWriter; |
| import java.util.Map; |
| |
| import org.objectweb.asm.Attribute; |
| import org.objectweb.asm.ByteVector; |
| import org.objectweb.asm.ClassReader; |
| import org.objectweb.asm.ClassVisitor; |
| import org.objectweb.asm.ClassWriter; |
| import org.objectweb.asm.FieldVisitor; |
| import org.objectweb.asm.Label; |
| import org.objectweb.asm.MethodVisitor; |
| import org.objectweb.asm.Opcodes; |
| import org.objectweb.asm.util.Textifiable; |
| import org.objectweb.asm.util.TraceClassVisitor; |
| |
| /** |
| * @author Eric Bruneton |
| */ |
| public class Attributes extends ClassLoader { |
| |
| public static void main(final String args[]) throws Exception { |
| // loads the original class and adapts it |
| ClassReader cr = new ClassReader("CommentAttribute"); |
| ClassWriter cw = new ClassWriter(0); |
| ClassVisitor cv = new AddCommentClassAdapter(cw); |
| cr.accept(cv, new Attribute[] { new CommentAttribute("") }, 0); |
| byte[] b = cw.toByteArray(); |
| |
| // stores the adapted class on disk |
| FileOutputStream fos = new FileOutputStream( |
| "CommentAttribute.class.new"); |
| try { |
| fos.write(b); |
| } finally { |
| fos.close(); |
| } |
| |
| // "disassembles" the adapted class |
| cr = new ClassReader(b); |
| cv = new TraceClassVisitor(new PrintWriter(System.out)); |
| cr.accept(cv, new Attribute[] { new CommentAttribute("") }, 0); |
| } |
| } |
| |
| class AddCommentClassAdapter extends ClassVisitor implements Opcodes { |
| |
| public AddCommentClassAdapter(final ClassVisitor cv) { |
| super(Opcodes.ASM4, cv); |
| } |
| |
| @Override |
| public void visit(final int version, final int access, final String name, |
| final String signature, final String superName, |
| final String[] interfaces) { |
| super.visit(version, access, name, signature, superName, interfaces); |
| visitAttribute(new CommentAttribute("this is a class comment")); |
| } |
| |
| @Override |
| public FieldVisitor visitField(final int access, final String name, |
| final String desc, final String signature, final Object value) { |
| FieldVisitor fv = super |
| .visitField(access, name, desc, signature, value); |
| fv.visitAttribute(new CommentAttribute("this is a field comment")); |
| return fv; |
| } |
| |
| @Override |
| public MethodVisitor visitMethod(final int access, final String name, |
| final String desc, final String signature, final String[] exceptions) { |
| MethodVisitor mv = cv.visitMethod(access, name, desc, signature, |
| exceptions); |
| if (mv != null) { |
| mv.visitAttribute(new CommentAttribute("this is a method comment")); |
| } |
| return mv; |
| } |
| } |
| |
| class CommentAttribute extends Attribute implements Textifiable { |
| |
| private String comment; |
| |
| public CommentAttribute(final String comment) { |
| super("Comment"); |
| this.comment = comment; |
| } |
| |
| public String getComment() { |
| return comment; |
| } |
| |
| @Override |
| public boolean isUnknown() { |
| return false; |
| } |
| |
| @Override |
| protected Attribute read(final ClassReader cr, final int off, |
| final int len, final char[] buf, final int codeOff, |
| final Label[] labels) { |
| return new CommentAttribute(cr.readUTF8(off, buf)); |
| } |
| |
| @Override |
| protected ByteVector write(final ClassWriter cw, final byte[] code, |
| final int len, final int maxStack, final int maxLocals) { |
| return new ByteVector().putShort(cw.newUTF8(comment)); |
| } |
| |
| public void textify(StringBuffer buf, Map<Label, String> labelNames) { |
| buf.append(": " + comment + "\n"); |
| } |
| } |