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.falcon.service; import org.apache.commons.lang.StringUtils; import org.apache.falcon.FalconException; import org.apache.falcon.persistence.EntityBean; import org.apache.falcon.persistence.InstanceBean; import org.apache.falcon.util.StateStoreProperties; import org.apache.openjpa.persistence.OpenJPAEntityManagerFactorySPI; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; import java.text.MessageFormat; import java.util.Properties; /** * Service that manages JPA. */ public final class FalconJPAService implements FalconService { private static final Logger LOG = LoggerFactory.getLogger(FalconJPAService.class); public static final String PREFIX = "falcon.statestore."; public static final String DB_SCHEMA = PREFIX + "schema.name"; public static final String URL = PREFIX + "jdbc.url"; public static final String DRIVER = PREFIX + "jdbc.driver"; public static final String USERNAME = PREFIX + "jdbc.username"; public static final String PASSWORD = PREFIX + "jdbc.password"; public static final String CONN_DATA_SOURCE = PREFIX + "connection.data.source"; public static final String CONN_PROPERTIES = PREFIX + "connection.properties"; public static final String MAX_ACTIVE_CONN = PREFIX + "pool.max.active.conn"; public static final String CREATE_DB_SCHEMA = PREFIX + "create.db.schema"; public static final String VALIDATE_DB_CONN = PREFIX + "validate.db.connection"; public static final String VALIDATE_DB_CONN_EVICTION_INTERVAL = PREFIX + "validate.db.connection.eviction.interval"; public static final String VALIDATE_DB_CONN_EVICTION_NUM = PREFIX + "validate.db.connection.eviction.num"; private EntityManagerFactory entityManagerFactory; // Persistent Unit which is defined in persistence.xml private String persistenceUnit; private static final FalconJPAService FALCON_JPA_SERVICE = new FalconJPAService(); private FalconJPAService() { } public static FalconJPAService get() { return FALCON_JPA_SERVICE; } public EntityManagerFactory getEntityManagerFactory() { return entityManagerFactory; } public void setPersistenceUnit(String dbType) { if (StringUtils.isEmpty(dbType)) { throw new IllegalArgumentException(" DB type cannot be null or empty"); } dbType = dbType.split(":")[0]; this.persistenceUnit = "falcon-" + dbType; } @Override public String getName() { return this.getClass().getSimpleName(); } @Override public void init() throws FalconException { Properties props = getPropsforStore(); entityManagerFactory = Persistence.createEntityManagerFactory(persistenceUnit, props); EntityManager entityManager = getEntityManager(); entityManager.find(EntityBean.class, 1); entityManager.find(InstanceBean.class, 1); LOG.info("All entities initialized"); // need to use a pseudo no-op transaction so all entities, datasource // and connection pool are initialized one time only entityManager.getTransaction().begin(); OpenJPAEntityManagerFactorySPI spi = (OpenJPAEntityManagerFactorySPI) entityManagerFactory; // Mask the password with '***' String logMsg = spi.getConfiguration().getConnectionProperties().replaceAll("Password=.*?,", "Password=***,"); LOG.info("JPA configuration: {0}", logMsg); entityManager.getTransaction().commit(); entityManager.close(); } private Properties getPropsforStore() throws FalconException { String dbSchema = StateStoreProperties.get().getProperty(DB_SCHEMA); String url = StateStoreProperties.get().getProperty(URL); String driver = StateStoreProperties.get().getProperty(DRIVER); String user = StateStoreProperties.get().getProperty(USERNAME); String password = StateStoreProperties.get().getProperty(PASSWORD).trim(); String maxConn = StateStoreProperties.get().getProperty(MAX_ACTIVE_CONN).trim(); String dataSource = StateStoreProperties.get().getProperty(CONN_DATA_SOURCE); String connPropsConfig = StateStoreProperties.get().getProperty(CONN_PROPERTIES); boolean autoSchemaCreation = Boolean .parseBoolean(StateStoreProperties.get().getProperty(CREATE_DB_SCHEMA, "false")); boolean validateDbConn = Boolean .parseBoolean(StateStoreProperties.get().getProperty(VALIDATE_DB_CONN, "true")); String evictionInterval = StateStoreProperties.get().getProperty(VALIDATE_DB_CONN_EVICTION_INTERVAL).trim(); String evictionNum = StateStoreProperties.get().getProperty(VALIDATE_DB_CONN_EVICTION_NUM).trim(); if (!url.startsWith("jdbc:")) { throw new FalconException("invalid JDBC URL, must start with 'jdbc:'" + url); } String dbType = url.substring("jdbc:".length()); if (dbType.indexOf(":") <= 0) { throw new FalconException("invalid JDBC URL, missing vendor 'jdbc:[VENDOR]:...'" + url); } setPersistenceUnit(dbType); String connProps = "DriverClassName={0},Url={1},Username={2},Password={3},MaxActive={4}"; connProps = MessageFormat.format(connProps, driver, url, user, password, maxConn); Properties props = new Properties(); if (autoSchemaCreation) { connProps += ",TestOnBorrow=false,TestOnReturn=false,TestWhileIdle=false"; props.setProperty("openjpa.jdbc.SynchronizeMappings", "buildSchema(ForeignKeys=true)"); } else if (validateDbConn) { // validation can be done only if the schema already exist, else a // connection cannot be obtained to create the schema. String interval = "timeBetweenEvictionRunsMillis=" + evictionInterval; String num = "numTestsPerEvictionRun=" + evictionNum; connProps += ",TestOnBorrow=true,TestOnReturn=true,TestWhileIdle=true," + interval + "," + num; connProps += ",ValidationQuery=select 1"; connProps = MessageFormat.format(connProps, dbSchema); } else { connProps += ",TestOnBorrow=false,TestOnReturn=false,TestWhileIdle=false"; } if (connPropsConfig != null) { connProps += "," + connPropsConfig; } props.setProperty("openjpa.ConnectionProperties", connProps); props.setProperty("openjpa.ConnectionDriverName", dataSource); return props; } @Override public void destroy() throws FalconException { if (entityManagerFactory.isOpen()) { entityManagerFactory.close(); } } /** * Return an EntityManager. Used by the StoreService. * * @return an entity manager */ public EntityManager getEntityManager() { return getEntityManagerFactory().createEntityManager(); } }