/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.deltaspike.jpa.api.transaction;
import org.apache.deltaspike.core.api.provider.BeanProvider;
import javax.enterprise.context.ApplicationScoped;
import java.util.concurrent.Callable;
/**
* <p></p>This class allows to execute CDI-unmanaged code blocks in a
* @Transactional manner. This is handy if you like e.g. to execute
* database code in a unit test tearDown method.</p>
*
* <p><b>Attention:</b> please be aware that this helper only works for
* @Transactional with auto-detecting the EntityManager!
* If you need to manually specify the EntityManager Qualifier
* for another EntityManager, then you need to copy this code and adopt it.</p>
* <p> Usage:
* <pre>
* SomeEntity retVal = TransactionHelper.getInstance().executeTransactional( new Callable<Integer>() {
* private @Inject EntityManager em;
* public SomeEntity call() throws Exception {
* return em.find(entityId, SomeEntity.class);
* }
* } );
* </pre>
* </p>
*/
@ApplicationScoped
public class TransactionHelper
{
public static TransactionHelper getInstance()
{
return BeanProvider.getContextualReference(TransactionHelper.class);
}
/**
* Execute the given {@link Callable} in a Transitional manner.
*
* @param callable which will get executed in a @Transactional block
* @param <T> the return type of the executed {@link Callable}
* @return the return value of the executed {@link Callable}
* @throws Exception
*/
@Transactional
public <T> T executeTransactional(Callable<T> callable) throws Exception
{
return callable.call();
}
}