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/***
* 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");
}
}
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