Java tutorial
/* * 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.shindig.social.opensocial.jpa.hibernate; import com.google.common.collect.Maps; import com.google.inject.Inject; import com.google.inject.name.Named; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.util.Map; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; /** * */ public class Bootstrap { private static final String DB_DRIVER = "db.driver"; private static final String DB_URL = "db.url"; private static final String DB_USER = "db.user"; private static final String DB_PASSWORD = "db.password"; private static final String DB_MIN_WRITE = "db.write.min"; private static final String DB_MIN_NUM_READ = "db.read.min"; private static final Log LOG = LogFactory.getLog(Boolean.class); private String minWrite; private String minRead; private String dbPassword; private String dbUser; private String dbUrl; private String dbDriver; private EntityManager entityManager; @Inject public Bootstrap(@Named(DB_DRIVER) String dbDriver, @Named(DB_URL) String dbUrl, @Named(DB_USER) String dbUser, @Named(DB_PASSWORD) String dbPassword, @Named(DB_MIN_NUM_READ) String minRead, @Named(DB_MIN_WRITE) String minWrite) { this.dbDriver = dbDriver; this.dbUrl = dbUrl; this.dbUser = dbUser; this.dbPassword = dbPassword == null || dbPassword.length() == 0 ? " " : dbPassword; this.minRead = minRead; this.minWrite = minWrite; } public Bootstrap() { } public void init(String unitName) { Map<String, String> properties = Maps.newHashMap(); LOG.info("Starting connection manager with properties " + properties); EntityManagerFactory emFactory = Persistence.createEntityManagerFactory(unitName, properties); entityManager = emFactory.createEntityManager(); } /** * @param string * @return */ public EntityManager getEntityManager(String unitName) { if (entityManager == null) { init(unitName); } return entityManager; } }