/** | |
* Copyright (C) 2010 Google, Inc. | |
* | |
* 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 com.google.inject.persist.jpa; | |
import com.google.inject.Inject; | |
import com.google.inject.Provider; | |
import com.google.inject.Singleton; | |
import com.google.inject.internal.Nullable; | |
import com.google.inject.internal.util.Preconditions; | |
import com.google.inject.persist.PersistModule; | |
import com.google.inject.persist.WorkManager; | |
import java.util.Properties; | |
import javax.persistence.EntityManager; | |
import javax.persistence.EntityManagerFactory; | |
import javax.persistence.Persistence; | |
/** | |
* @author Dhanji R. Prasanna (dhanji@gmail.com) | |
*/ | |
@Singleton | |
class EntityManagerProvider implements Provider<EntityManager>, WorkManager { | |
private final ThreadLocal<EntityManager> entityManager = new ThreadLocal<EntityManager>(); | |
private final String persistenceUnitName; | |
private final Properties persistenceProperties; | |
@Inject | |
public EntityManagerProvider(@PersistModule.Persist String persistenceUnitName, | |
@Nullable @PersistModule.Persist Properties persistenceProperties) { | |
this.persistenceUnitName = persistenceUnitName; | |
this.persistenceProperties = persistenceProperties; | |
} | |
public EntityManager get() { | |
if (!isWorking()) { | |
begin(); | |
} | |
EntityManager em = entityManager.get(); | |
Preconditions.checkState(null != em, "Requested EntityManager outside work unit. " | |
+ "Try calling WorkManager.begin() first, or use a PersistenceFilter if you " | |
+ "are inside a servlet environment."); | |
return em; | |
} | |
public boolean isWorking() { | |
return entityManager.get() != null; | |
} | |
public void begin() { | |
Preconditions.checkState(null == entityManager.get(), | |
"Work already begun on this thread. Looks like you have called WorkManager.begin() twice" | |
+ " without a balancing call to end() in between."); | |
entityManager.set(emFactory.createEntityManager()); | |
} | |
public void end() { | |
EntityManager em = entityManager.get(); | |
// Let's not penalize users for calling end() multiple times. | |
if (null == em) { | |
return; | |
} | |
em.close(); | |
entityManager.remove(); | |
} | |
private volatile EntityManagerFactory emFactory; | |
public synchronized void startPersistence() { | |
Preconditions.checkState(null == emFactory, "Persistence service was already initialized."); | |
if (null != persistenceProperties) { | |
this.emFactory = Persistence | |
.createEntityManagerFactory(persistenceUnitName, persistenceProperties); | |
} else { | |
this.emFactory = Persistence.createEntityManagerFactory(persistenceUnitName); | |
} | |
} | |
public synchronized void shutdownPersistence() { | |
Preconditions.checkState(emFactory.isOpen(), "Persistence service was already shut down."); | |
emFactory.close(); | |
} | |
@Singleton | |
public static class EntityManagerFactoryProvider implements Provider<EntityManagerFactory> { | |
private final EntityManagerProvider emProvider; | |
@Inject | |
public EntityManagerFactoryProvider(EntityManagerProvider emProvider) { | |
this.emProvider = emProvider; | |
} | |
public EntityManagerFactory get() { | |
assert null != emProvider.emFactory; | |
return emProvider.emFactory; | |
} | |
} | |
} |