| /**************************************************************** |
| * 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.james.backends.jpa; |
| |
| import java.util.function.Consumer; |
| import java.util.function.Function; |
| |
| import javax.persistence.EntityManager; |
| import javax.persistence.EntityManagerFactory; |
| import javax.persistence.EntityTransaction; |
| import javax.persistence.PersistenceException; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| public class TransactionRunner { |
| |
| private static final Logger LOGGER = LoggerFactory.getLogger(TransactionRunner.class); |
| public static final Function<PersistenceException, Object> IGNORE_EXCEPTION = e -> null; |
| |
| private final EntityManagerFactory entityManagerFactory; |
| |
| public TransactionRunner(EntityManagerFactory entityManagerFactory) { |
| this.entityManagerFactory = entityManagerFactory; |
| } |
| |
| public void run(Consumer<EntityManager> runnable) { |
| runAndRetrieveResult(entityManager -> { |
| runnable.accept(entityManager); |
| return null; |
| }, |
| IGNORE_EXCEPTION); |
| } |
| |
| public <T> T runAndRetrieveResult(Function<EntityManager, T> toResult) { |
| return runAndRetrieveResult(toResult, |
| e -> { |
| throw new RuntimeException(e); |
| }); |
| } |
| |
| public <T> T runAndRetrieveResult(Function<EntityManager, T> toResult, |
| Function<PersistenceException, T> errorHandler) { |
| EntityManager entityManager = entityManagerFactory.createEntityManager(); |
| EntityTransaction transaction = entityManager.getTransaction(); |
| try { |
| transaction.begin(); |
| T result = toResult.apply(entityManager); |
| transaction.commit(); |
| return result; |
| } catch (PersistenceException e) { |
| LOGGER.warn("Could not execute transaction", e); |
| if (transaction.isActive()) { |
| transaction.rollback(); |
| } |
| return errorHandler.apply(e); |
| } finally { |
| EntityManagerUtils.safelyClose(entityManager); |
| } |
| } |
| |
| public void runAndHandleException(Consumer<EntityManager> runnable, |
| Consumer<PersistenceException> errorHandler) { |
| EntityManager entityManager = entityManagerFactory.createEntityManager(); |
| EntityTransaction transaction = entityManager.getTransaction(); |
| try { |
| transaction.begin(); |
| runnable.accept(entityManager); |
| transaction.commit(); |
| } catch (PersistenceException e) { |
| LOGGER.warn("Could not execute transaction", e); |
| if (transaction.isActive()) { |
| transaction.rollback(); |
| } |
| errorHandler.accept(e); |
| } finally { |
| EntityManagerUtils.safelyClose(entityManager); |
| } |
| } |
| } |