com.blazebit.job.transaction.jpa.JpaTransactionSupport Maven / Gradle / Ivy
/*
* Copyright 2018 - 2019 Blazebit.
*
* 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.blazebit.job.transaction.jpa;
import com.blazebit.apt.service.ServiceProvider;
import com.blazebit.job.JobContext;
import com.blazebit.job.spi.TransactionSupport;
import javax.persistence.EntityManager;
import javax.persistence.EntityTransaction;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.function.Consumer;
/**
* A JPA-based implementation for {@link TransactionSupport}.
*
* @author Christian Beikov
* @since 1.0.0
*/
@ServiceProvider(TransactionSupport.class)
public class JpaTransactionSupport implements TransactionSupport {
private final ThreadLocal transactionStackThreadLocal = new ThreadLocal<>();
@Override
public T transactional(JobContext context, long transactionTimeoutMillis, boolean joinIfPossible, Callable callable, Consumer exceptionHandler) {
EntityManager entityManager = context.getService(EntityManager.class);
EntityTransaction entityTransaction = entityManager.getTransaction();
TransactionStack transactionStack = transactionStackThreadLocal.get();
boolean root = false;
int index = -1;
if (transactionStack == null) {
transactionStack = new TransactionStack();
transactionStack.entityTransactions.add(entityTransaction);
entityTransaction.begin();
root = true;
transactionStackThreadLocal.set(transactionStack);
} else if (!joinIfPossible || transactionStack.entityTransactions.get(0).getRollbackOnly()) {
entityManager = entityManager.getEntityManagerFactory().createEntityManager();
index = transactionStack.entityTransactions.size();
transactionStack.entityTransactions.add(entityTransaction = entityManager.getTransaction());
entityTransaction.begin();
}
boolean success = true;
try {
return callable.call();
} catch (Throwable t) {
success = false;
exceptionHandler.accept(t);
return null;
} finally {
if (root) {
transactionStackThreadLocal.remove();
if (success) {
entityTransaction.commit();
for (Runnable postCommitListener : transactionStack.postCommitListeners) {
postCommitListener.run();
}
} else {
entityTransaction.rollback();
}
} else if (index != -1) {
transactionStack.entityTransactions.remove(index);
if (success) {
entityTransaction.commit();
} else {
entityTransaction.rollback();
}
}
}
}
/**
* @author Christian Beikov
* @since 1.0.0
*/
private static class TransactionStack {
private final List entityTransactions = new ArrayList<>();
private final List postCommitListeners = new ArrayList<>();
}
@Override
public void registerPostCommitListener(Runnable o) {
TransactionStack transactionStack = transactionStackThreadLocal.get();
if (transactionStack == null) {
throw new IllegalStateException("No active transaction!");
}
transactionStack.postCommitListeners.add(o);
}
}