/*
* Copyright 2010 salaboy.
*
* 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.
* under the License.
*/
package org.drools.persistence.jpa.marshaller;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Id;
import org.drools.common.DroolsObjectInputStream;
import org.drools.marshalling.ObjectMarshallingStrategy;
import org.drools.runtime.Environment;
import org.drools.runtime.EnvironmentName;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class JPAPlaceholderResolverStrategy implements ObjectMarshallingStrategy {
private static Logger log = LoggerFactory.getLogger(JPAPlaceholderResolverStrategy.class);
private Environment env;
public JPAPlaceholderResolverStrategy(Environment env) {
this.env = env;
}
public boolean accept(Object object) {
return isEntity(object);
}
public void write(ObjectOutputStream os, Object object) throws IOException {
os.writeUTF(object.getClass().getCanonicalName());
os.writeObject(getClassIdValue(object));
}
public Object read(ObjectInputStream is) throws IOException, ClassNotFoundException {
String canonicalName = is.readUTF();
Object id = is.readObject();
EntityManagerFactory emf = (EntityManagerFactory) env.get(EnvironmentName.ENTITY_MANAGER_FACTORY);
EntityManager em = emf.createEntityManager();
return em.find(Class.forName(canonicalName), id);
}
public byte[] marshal(Context context,
ObjectOutputStream os,
Object object) throws IOException {
ByteArrayOutputStream buff = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream( buff );
oos.writeUTF(object.getClass().getCanonicalName());
oos.writeObject(getClassIdValue(object));
oos.close();
return buff.toByteArray();
}
public Object unmarshal(Context context,
ObjectInputStream ois,
byte[] object,
ClassLoader classloader) throws IOException,
ClassNotFoundException {
DroolsObjectInputStream is = new DroolsObjectInputStream( new ByteArrayInputStream( object ), classloader );
String canonicalName = is.readUTF();
Object id = is.readObject();
EntityManagerFactory emf = (EntityManagerFactory) env.get(EnvironmentName.ENTITY_MANAGER_FACTORY);
EntityManager em = emf.createEntityManager();
return em.find(Class.forName(canonicalName), id);
}
public Context createContext() {
// no need for context
return null;
}
public static Serializable getClassIdValue(Object o) {
Class<? extends Object> varClass = o.getClass();
Serializable idValue = null;
try{
do {
Field[] fields = varClass.getDeclaredFields();
for (int i = 0; i < fields.length && idValue == null; i++) {
Field field = fields[i];
Id id = field.getAnnotation(Id.class);
if (id != null) {
try {
idValue = callIdMethod(o, "get"
+ Character.toUpperCase(field.getName().charAt(0))
+ field.getName().substring(1));
} catch (NoSuchMethodException e) {
idValue = (Serializable) field.get(o);
}
}
}
} while ((varClass = varClass.getSuperclass()) != null && idValue == null);
if (idValue == null) {
varClass = o.getClass();
do {
Method[] methods = varClass.getMethods();
for (int i = 0; i < methods.length && idValue == null; i++) {
Method method = methods[i];
Id id = method.getAnnotation(Id.class);
if (id != null) {
idValue = (Serializable) method.invoke(o);
}
}
} while ((varClass = varClass.getSuperclass()) != null && idValue == null);
}
}
catch(Exception ex){
log.error(ex.getMessage());
}
return idValue;
}
private static Serializable callIdMethod(Object target, String methodName) throws IllegalArgumentException,
SecurityException, IllegalAccessException, InvocationTargetException, NoSuchMethodException {
return (Serializable) target.getClass().getMethod(methodName, (Class[]) null).invoke(target, new Object[]{});
}
private static boolean isEntity(Object o){
Class<? extends Object> varClass = o.getClass();
do {
Field[] fields = varClass.getDeclaredFields();
for (int i = 0; i < fields.length; i++) {
Field field = fields[i];
Id id = field.getAnnotation(Id.class);
if (id != null) {
return true;
}
}
} while ((varClass = varClass.getSuperclass()) != null);
varClass = o.getClass();
do {
Method[] methods = varClass.getMethods();
for (int i = 0; i < methods.length; i++) {
Method method = methods[i];
Id id = method.getAnnotation(Id.class);
if (id != null) {
return true;
}
}
} while ((varClass = varClass.getSuperclass()) != null );
return false;
}
}