/*
* Copyright 2002-2008 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.core;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectStreamClass;
import java.lang.reflect.Proxy;
import org.springframework.util.ClassUtils;
/**
* Special ObjectInputStream subclass that resolves class names
* against a specific ClassLoader. Serves as base class for
* {@link org.springframework.remoting.rmi.CodebaseAwareObjectInputStream}.
*
* @author Juergen Hoeller
* @since 2.5.5
*/
public class ConfigurableObjectInputStream extends ObjectInputStream {
private final ClassLoader classLoader;
/**
* Create a new ConfigurableObjectInputStream for the given InputStream and ClassLoader.
* @param in the InputStream to read from
* @param classLoader the ClassLoader to use for loading local classes
* @see java.io.ObjectInputStream#ObjectInputStream(java.io.InputStream)
*/
public ConfigurableObjectInputStream(InputStream in, ClassLoader classLoader) throws IOException {
super(in);
this.classLoader = classLoader;
}
@Override
protected Class resolveClass(ObjectStreamClass classDesc) throws IOException, ClassNotFoundException {
try {
if (this.classLoader != null) {
// Use the specified ClassLoader to resolve local classes.
return ClassUtils.forName(classDesc.getName(), this.classLoader);
}
else {
// Use the default ClassLoader...
return super.resolveClass(classDesc);
}
}
catch (ClassNotFoundException ex) {
return resolveFallbackIfPossible(classDesc.getName(), ex);
}
}
@Override
protected Class resolveProxyClass(String[] interfaces) throws IOException, ClassNotFoundException {
if (this.classLoader != null) {
// Use the specified ClassLoader to resolve local proxy classes.
Class[] resolvedInterfaces = new Class[interfaces.length];
for (int i = 0; i < interfaces.length; i++) {
try {
resolvedInterfaces[i] = ClassUtils.forName(interfaces[i], this.classLoader);
}
catch (ClassNotFoundException ex) {
resolvedInterfaces[i] = resolveFallbackIfPossible(interfaces[i], ex);
}
}
try {
return Proxy.getProxyClass(this.classLoader, resolvedInterfaces);
}
catch (IllegalArgumentException ex) {
throw new ClassNotFoundException(null, ex);
}
}
else {
// Use ObjectInputStream's default ClassLoader...
try {
return super.resolveProxyClass(interfaces);
}
catch (ClassNotFoundException ex) {
Class[] resolvedInterfaces = new Class[interfaces.length];
for (int i = 0; i < interfaces.length; i++) {
resolvedInterfaces[i] = resolveFallbackIfPossible(interfaces[i], ex);
}
return Proxy.getProxyClass(getFallbackClassLoader(), resolvedInterfaces);
}
}
}
/**
* Resolve the given class name against a fallback class loader.
* <p>The default implementation simply rethrows the original exception,
* since there is no fallback available.
* @param className the class name to resolve
* @param ex the original exception thrown when attempting to load the class
* @return the newly resolved class (never <code>null</code>)
*/
protected Class resolveFallbackIfPossible(String className, ClassNotFoundException ex)
throws IOException, ClassNotFoundException{
throw ex;
}
/**
* Return the fallback ClassLoader to use when no ClassLoader was specified
* and ObjectInputStream's own default ClassLoader failed.
* <p>The default implementation simply returns <code>null</code>.
*/
protected ClassLoader getFallbackClassLoader() throws IOException {
return null;
}
}
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