org.springframework.instrument.classloading.weblogic.WebLogicClassPreProcessorAdapter Maven / Gradle / Ivy
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/*
* Copyright 2002-2014 the original author or authors.
*
* 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.springframework.instrument.classloading.weblogic;
import java.lang.instrument.ClassFileTransformer;
import java.lang.instrument.IllegalClassFormatException;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.util.Hashtable;
/**
* Adapter that implements WebLogic ClassPreProcessor interface, delegating to a
* standard JDK {@link ClassFileTransformer} underneath.
*
* To avoid compile time checks again the vendor API, a dynamic proxy is
* being used.
*
* @author Costin Leau
* @author Juergen Hoeller
* @since 2.5
*/
class WebLogicClassPreProcessorAdapter implements InvocationHandler {
private final ClassFileTransformer transformer;
private final ClassLoader loader;
/**
* Creates a new {@link WebLogicClassPreProcessorAdapter}.
* @param transformer the {@link ClassFileTransformer} to be adapted
* (must not be {@code null})
*/
public WebLogicClassPreProcessorAdapter(ClassFileTransformer transformer, ClassLoader loader) {
this.transformer = transformer;
this.loader = loader;
}
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
String name = method.getName();
if ("equals".equals(name)) {
return (proxy == args[0]);
}
else if ("hashCode".equals(name)) {
return hashCode();
}
else if ("toString".equals(name)) {
return toString();
}
else if ("initialize".equals(name)) {
initialize((Hashtable) args[0]);
return null;
}
else if ("preProcess".equals(name)) {
return preProcess((String) args[0], (byte[]) args[1]);
}
else {
throw new IllegalArgumentException("Unknown method: " + method);
}
}
public void initialize(Hashtable params) {
}
public byte[] preProcess(String className, byte[] classBytes) {
try {
byte[] result = this.transformer.transform(this.loader, className, null, null, classBytes);
return (result != null ? result : classBytes);
}
catch (IllegalClassFormatException ex) {
throw new IllegalStateException("Cannot transform due to illegal class format", ex);
}
}
@Override
public String toString() {
return getClass().getName() + " for transformer: " + this.transformer;
}
}