/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* 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 eu.stratosphere.api.common.operators.util;
import java.io.Serializable;
import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import com.google.common.base.Preconditions;
import eu.stratosphere.api.common.NonSerializableUserCodeException;
/**
* This holds an actual object containing user defined code.
*/
public class UserCodeObjectWrapper<T> implements UserCodeWrapper<T> {
private static final long serialVersionUID = 1L;
private final T userCodeObject;
public UserCodeObjectWrapper(T userCodeObject) {
Preconditions.checkNotNull(userCodeObject, "The user code object may not be null.");
Preconditions.checkArgument(userCodeObject instanceof Serializable, "User code object is not serializable: " + userCodeObject.getClass().getName());
this.userCodeObject = userCodeObject;
// Remove non serializable objects from the user code object as well as from outer objects
Object current = userCodeObject;
try {
while (null != current) {
Object newCurrent = null;
/**
* Check if the usercode class has custom serialization methods.
* (See http://docs.oracle.com/javase/7/docs/api/java/io/Serializable.html for details).
* We can not guarantee that the user handles serialization correctly in this case.
*/
boolean hasCustomSerialization = false;
Method customSerializer = null;
Method customDeserializer = null;
try {
customSerializer = current.getClass().getDeclaredMethod("writeObject", java.io.ObjectOutputStream.class);
customDeserializer = current.getClass().getDeclaredMethod("readObject", java.io.ObjectInputStream.class);
} catch (Exception e) {
// we can ignore exceptions here.
}
if (customSerializer != null && customDeserializer != null) {
hasCustomSerialization = true;
}
for (Field f : current.getClass().getDeclaredFields()) {
f.setAccessible(true);
if (f.getName().contains("$outer")) {
newCurrent = f.get(current);
}
if (hasCustomSerialization || Modifier.isTransient(f.getModifiers()) || Modifier.isStatic(f.getModifiers())) {
// field not relevant for serialization
continue;
}
Object fieldContents = f.get(current);
if (fieldContents != null && !(fieldContents instanceof Serializable)) {
throw new NonSerializableUserCodeException("User-defined object " + userCodeObject + " (" +
userCodeObject.getClass().getName() + ") contains non-serializable field " +
f.getName() + " = " + f.get(current));
}
}
current = newCurrent;
}
}
catch (NonSerializableUserCodeException e) {
// forward those
throw e;
}
catch (Exception e) {
// should never happen, since we make the fields accessible.
// anyways, do not swallow the exception, but report it
throw new RuntimeException("Could not access the fields of the user defined class while checking for serializability.", e);
}
}
@Override
public T getUserCodeObject(Class<? super T> superClass, ClassLoader cl) {
return userCodeObject;
}
@Override
public T getUserCodeObject() {
return userCodeObject;
}
@Override
public <A extends Annotation> A getUserCodeAnnotation(Class<A> annotationClass) {
return userCodeObject.getClass().getAnnotation(annotationClass);
}
@SuppressWarnings("unchecked")
@Override
public Class<? extends T> getUserCodeClass() {
return (Class<? extends T>) userCodeObject.getClass();
}
}