/**************************************************************************************
* Copyright (c) Jonas Bon?r, Alexandre Vasseur. All rights reserved. *
* http://aspectwerkz.codehaus.org *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the LGPL license *
* a copy of which has been included with this distribution in the license.txt file. *
**************************************************************************************/
package org.codehaus.aspectwerkz.annotation.instrumentation.asm;
import org.objectweb.asm.attrs.Annotation;
import org.objectweb.asm.attrs.RuntimeInvisibleAnnotations;
import org.objectweb.asm.Attribute;
import org.codehaus.aspectwerkz.util.Base64;
import org.codehaus.aspectwerkz.UnbrokenObjectInputStream;
import org.codehaus.aspectwerkz.annotation.AnnotationInfo;
import org.codehaus.aspectwerkz.exception.WrappedRuntimeException;
import java.io.ByteArrayInputStream;
/**
* Helper class to wrap a custom annotation proxy (1.3/1.4 javadoc annotation) in a RuntimeInvisibleAnnotations.
* <br/>
* The proxy is wrapped in a AnnotationInfo object which is serialized
* and base64 encoded (ASM issue on array types in RIV).
*
* @author <a href="mailto:alex@gnilux.com">Alexandre Vasseur</a>
*/
public class CustomAttributeHelper {
/**
* Annotation parameter - as if it was a single value Tiger annotation
*/
private final static String VALUE = "value";
/**
* Extract the AnnotationInfo from the bytecode Annotation representation.
*
* @param annotation must be a valid RIV, of type CustomAttribute.TYPE
* @return
*/
public static AnnotationInfo extractCustomAnnotation(final Annotation annotation) {
byte[] bytes = Base64.decode((String)((Object[])annotation.elementValues.get(0))[1]);
return extractCustomAnnotation(bytes);
}
/**
* Extract the AnnotationInfo from the base64 encoded serialized version.
* @param bytes
* @return
*/
public static AnnotationInfo extractCustomAnnotation(final byte[] bytes) {
try {
Object userAnnotation = new UnbrokenObjectInputStream(new ByteArrayInputStream(bytes)).readObject();
if (userAnnotation instanceof AnnotationInfo) {
return (AnnotationInfo)userAnnotation;
} else {
// should not occur
throw new RuntimeException("Custom annotation is not wrapped in AnnotationInfo: "
+ userAnnotation.getClass().getName()
+ " in " + userAnnotation.getClass().getClassLoader() + ". AnnotationInfo is in "
+ AnnotationInfo.class.getClassLoader());
}
} catch (Exception e) {
throw new WrappedRuntimeException(e);
}
}
/**
* Create an Annotation bytecode representation from the serialized version of the custom annotation proxy
* @param bytes
* @return
*/
public static Annotation createCustomAnnotation(final byte[] bytes) {
Annotation annotation = new Annotation();
annotation.type = CustomAttribute.TYPE;
annotation.add(VALUE, Base64.encodeBytes(bytes));
return annotation;
}
/**
* Helper method to find the first RuntimeInvisibleAnnotations attribute in an Attribute chain.
* <br/>If no such RIV exists, a new one is created (empty) and added last in the chain.
* <br/>If the chain is null, a new sole RIV (empty) is created
*
* @param attribute
* @return the RuntimeInvisibleAnnotations to add Annotation to
*/
public static RuntimeInvisibleAnnotations linkRuntimeInvisibleAnnotations(final Attribute attribute) {
RuntimeInvisibleAnnotations runtimeInvisibleAnnotations = null;
Attribute lastAttribute = attribute;
for (Attribute loop = attribute; loop != null; loop = loop.next) {
lastAttribute = loop;
if (loop instanceof RuntimeInvisibleAnnotations) {
return runtimeInvisibleAnnotations = (RuntimeInvisibleAnnotations)loop;
}
}
// not found, link a new one to lastAttribute
runtimeInvisibleAnnotations = new RuntimeInvisibleAnnotations();
runtimeInvisibleAnnotations.next = null;
if (attribute != null) {
// if arg is null, we are just adding this annotation as the sole attribute
lastAttribute.next = runtimeInvisibleAnnotations;
} else {
//attribute = runtimeInvisibleAnnotations;
}
return runtimeInvisibleAnnotations;
}
}