TransactionFacade.java

/**
 * Copyright (C) 2012 Stephan Classen
 * Based on guice-perist (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.github.sclassen.guicejpa;

import javax.persistence.EntityTransaction;
import javax.transaction.UserTransaction;

/**
 * Interface which hides away the details of inner (nested) and outer transactions as well
 * as the details between {@link EntityTransaction} and {@link UserTransaction}.
 */
interface TransactionFacade {

  /**
   * Starts a transaction.
   * <p/>
   * The first call to begin will start the actual transaction. Subsequent calls will start a
   * 'nested' transaction.
   */
  void begin();

  /**
   * Commits a transaction.
   * <p/>
   * Only the actual transaction can be committed. Calls to commit on nested transactions have
   * no effect.
   */
  void commit();

  /**
   * Rolls a transaction back.
   * <p/>
   * Only the actual transaction can be rolled back. Calls to rollback on nested transactions will
   * set the onlyRollBack flag on the actual transaction. Setting this flag wil cause an actual
   * transaction to be rolled back in any case.
   */
  void rollback();

}