org.drools.persistence.jpa.marshaller.JPAPlaceholderResolverStrategy Maven / Gradle / Ivy
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JPA implementation for Drools
/*
* 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 javax.persistence.Persistence;
import org.drools.core.common.DroolsObjectInputStream;
import org.drools.core.marshalling.impl.MarshallerWriteContext;
import org.drools.core.marshalling.impl.ProcessMarshallerWriteContext;
import org.drools.persistence.TransactionAware;
import org.drools.persistence.TransactionManager;
import org.kie.api.marshalling.ObjectMarshallingStrategy;
import org.kie.api.runtime.Environment;
import org.kie.api.runtime.EnvironmentName;
import org.kie.internal.runtime.Cacheable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class JPAPlaceholderResolverStrategy implements ObjectMarshallingStrategy, TransactionAware, Cacheable {
private static Logger log = LoggerFactory.getLogger(JPAPlaceholderResolverStrategy.class);
private EntityManagerFactory emf;
private ClassLoader classLoader;
private boolean closeEmf = false;
private static final ThreadLocal persister = new ThreadLocal();
public JPAPlaceholderResolverStrategy(Environment env) {
this.emf = (EntityManagerFactory) env.get(EnvironmentName.ENTITY_MANAGER_FACTORY);
}
public JPAPlaceholderResolverStrategy(EntityManagerFactory emf) {
this.emf = emf;
}
public JPAPlaceholderResolverStrategy(String persistenceUnit, ClassLoader cl) {
ClassLoader tccl = Thread.currentThread().getContextClassLoader();
try {
// override tccl so persistence unit can be found from within given class loader - e.g. kjar
Thread.currentThread().setContextClassLoader(cl);
this.emf = Persistence.createEntityManagerFactory(persistenceUnit);
this.closeEmf = true;
} finally {
Thread.currentThread().setContextClassLoader(tccl);
}
this.classLoader = cl;
}
public boolean accept(Object object) {
return isEntity(object);
}
public void write(ObjectOutputStream os, Object object) throws IOException {
Object id = getClassIdValue(object);
EntityManager em = getEntityManager();
if (id == null) {
em.persist(object);
id = getClassIdValue(object);
} else {
em.merge(object);
}
// since this is invoked by marshaller it's safe to call flush
// and it's important to be flushed so subsequent unmarshall operations
// will get update content especially when merged
em.flush();
os.writeUTF(object.getClass().getCanonicalName());
os.writeObject(id);
}
public Object read(ObjectInputStream is) throws IOException, ClassNotFoundException {
String canonicalName = is.readUTF();
Object id = is.readObject();
EntityManager em = getEntityManager();
return em.find(Class.forName(canonicalName), id);
}
public byte[] marshal(Context context,
ObjectOutputStream os,
Object object) throws IOException {
Object id = getClassIdValue(object);
String entityType = object.getClass().getCanonicalName();
EntityManager em = getEntityManager();
if (id == null) {
em.persist(object);
id = getClassIdValue(object);
} else {
em.merge(object);
}
addMapping(id, entityType, object, os, em);
em.merge(object);
// since this is invoked by marshaller it's safe to call flush
// and it's important to be flushed so subsequent unmarshall operations
// will get update content especially when merged
em.flush();
ByteArrayOutputStream buff = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream( buff );
oos.writeUTF(entityType);
oos.writeObject(id);
oos.close();
return buff.toByteArray();
}
public Object unmarshal(Context context,
ObjectInputStream ois,
byte[] object,
ClassLoader classloader) throws IOException,
ClassNotFoundException {
ClassLoader clToUse = classloader;
if (this.classLoader != null) {
clToUse = this.classLoader;
}
DroolsObjectInputStream is = new DroolsObjectInputStream( new ByteArrayInputStream( object ), clToUse );
String canonicalName = is.readUTF();
Object id = is.readObject();
EntityManager em = getEntityManager();
return em.find(Class.forName(canonicalName, true, (clToUse==null?this.getClass().getClassLoader():clToUse)), id);
}
public Context createContext() {
// no need for context
return null;
}
public static Serializable getClassIdValue(Object o) {
Class 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 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;
}
@Override
public void onStart(TransactionManager txm) {
if (persister.get() == null) {
EntityManager em = emf.createEntityManager();
persister.set(em);
}
}
@Override
public void onEnd(TransactionManager txm) {
EntityManager em = persister.get();
if (em != null) {
em.close();
persister.set(null);
}
}
protected EntityManager getEntityManager() {
EntityManager em = persister.get();
if (em != null) {
return em;
}
return emf.createEntityManager();
}
@Override
public void close() {
if (closeEmf && this.emf != null) {
this.emf.close();
this.emf = null;
}
}
protected void addMapping(Object entityId, String entityType, Object entity, ObjectOutputStream context, EntityManager em) {
if (entityId instanceof Number && entity instanceof VariableEntity && context instanceof ProcessMarshallerWriteContext) {
ProcessMarshallerWriteContext processContext = (ProcessMarshallerWriteContext) context;
VariableEntity variableEntity = (VariableEntity) entity;
MappedVariable mappedVariable = new MappedVariable(((Number)entityId).longValue(), entityType, processContext.getProcessInstanceId(), processContext.getTaskId(), processContext.getWorkItemId());
if (processContext.getState() == ProcessMarshallerWriteContext.STATE_ACTIVE) {
variableEntity.addMappedVariables(mappedVariable);
} else {
MappedVariable toBeRemoved = variableEntity.findMappedVariables(mappedVariable);
if (toBeRemoved != null) {
toBeRemoved = em.find(MappedVariable.class, toBeRemoved.getMappedVarId());
em.remove(toBeRemoved);
variableEntity.removeMappedVariables(toBeRemoved);
}
}
}
}
}
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