org.springframework.instrument.classloading.weblogic.WebLogicClassLoader Maven / Gradle / Ivy
/*
* Copyright 2002-2007 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.reflect.Constructor;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import org.springframework.util.Assert;
/**
* Reflective wrapper around a WebLogic 10 class loader. Used to
* encapsulate the classloader-specific methods (discovered and
* called through reflection) from the load-time weaver.
*
* @author Costin Leau
* @author Juergen Hoeller
* @since 2.5
*/
class WebLogicClassLoader {
private static final String GENERIC_CLASS_LOADER_NAME = "weblogic.utils.classloaders.GenericClassLoader";
private static final String CLASS_PRE_PROCESSOR_NAME = "weblogic.utils.classloaders.ClassPreProcessor";
private final ClassLoader internalClassLoader;
private final Class wlPreProcessorClass;
private final Method addPreProcessorMethod;
private final Method getClassFinderMethod;
private final Method getParentMethod;
private final Constructor wlGenericClassLoaderConstructor;
public WebLogicClassLoader(ClassLoader classLoader) {
Class wlGenericClassLoaderClass = null;
try {
wlGenericClassLoaderClass = classLoader.loadClass(GENERIC_CLASS_LOADER_NAME);
this.wlPreProcessorClass = classLoader.loadClass(CLASS_PRE_PROCESSOR_NAME);
this.addPreProcessorMethod = classLoader.getClass().getMethod(
"addInstanceClassPreProcessor", this.wlPreProcessorClass);
this.getClassFinderMethod = classLoader.getClass().getMethod("getClassFinder");
this.getParentMethod = classLoader.getClass().getMethod("getParent");
this.wlGenericClassLoaderConstructor = wlGenericClassLoaderClass.getConstructor(
this.getClassFinderMethod.getReturnType(), ClassLoader.class);
}
catch (Exception ex) {
throw new IllegalStateException(
"Could not initialize WebLogic ClassLoader because WebLogic 10 API classes are not available", ex);
}
Assert.isInstanceOf(wlGenericClassLoaderClass, classLoader,
"ClassLoader must be instance of [" + wlGenericClassLoaderClass.getName() + "]");
this.internalClassLoader = classLoader;
}
public void addTransformer(ClassFileTransformer transformer) {
Assert.notNull(transformer, "ClassFileTransformer must not be null");
try {
InvocationHandler adapter = new WebLogicClassPreProcessorAdapter(transformer, this.internalClassLoader);
Object adapterInstance = Proxy.newProxyInstance(this.wlPreProcessorClass.getClassLoader(),
new Class[] {this.wlPreProcessorClass}, adapter);
this.addPreProcessorMethod.invoke(this.internalClassLoader, adapterInstance);
}
catch (InvocationTargetException ex) {
throw new IllegalStateException("WebLogic addInstanceClassPreProcessor method threw exception", ex.getCause());
}
catch (Exception ex) {
throw new IllegalStateException("Could not invoke WebLogic addInstanceClassPreProcessor method", ex);
}
}
public ClassLoader getInternalClassLoader() {
return this.internalClassLoader;
}
public ClassLoader getThrowawayClassLoader() {
try {
Object classFinder = this.getClassFinderMethod.invoke(this.internalClassLoader);
Object parent = this.getParentMethod.invoke(this.internalClassLoader);
// arguments for 'clone'-like method
return (ClassLoader) this.wlGenericClassLoaderConstructor.newInstance(classFinder, parent);
}
catch (InvocationTargetException ex) {
throw new IllegalStateException("WebLogic GenericClassLoader constructor failed", ex.getCause());
}
catch (Exception ex) {
throw new IllegalStateException("Could not construct WebLogic GenericClassLoader", ex);
}
}
}