Java tutorial
/* * This file is part of anycook. The new internet cookbook * Copyright (C) 2014 Jan Graegger * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see [http://www.gnu.org/licenses/]. */ package de.anycook.db.mysql; /** * enthaelt alle Funktion, die auf die MySQL-Datenbank zugreifen */ import com.google.common.base.Preconditions; import de.anycook.conf.Configuration; import org.apache.commons.dbcp2.BasicDataSource; import org.apache.logging.log4j.LogManager; import org.apache.logging.log4j.Logger; import java.sql.Connection; import java.sql.Driver; import java.sql.DriverManager; import java.sql.SQLException; import java.util.Enumeration; /** * Alle MySQL-Zugriffe geschehen ueber diese Klasse. Benutzt connectionpool * * @author Jan Grassegger */ public class DBHandler implements AutoCloseable { private static Logger sLogger = LogManager.getLogger(DBHandler.class); protected static BasicDataSource dataSource; public static void init() { String server = Configuration.getInstance().getMysqlAddress(); String db = Configuration.getInstance().getMysqlDb(); int port = Configuration.getInstance().getPropertyMysqlPort(); String user = Configuration.getInstance().getMysqlUser(); String password = Configuration.getInstance().getMysqlPassword(); int maxActive = Configuration.getInstance().getMysqlMaxActive(); int maxIdle = Configuration.getInstance().getMysqlMaxIdle(); dataSource = setupDataSource(server, port, db, user, password, maxActive, maxIdle); } protected Logger logger; protected Connection connection; /** * Laedt jdbc-Driver und ruft {@link de.anycook.db.mysql.DBHandler#connect()} auf. */ public DBHandler() throws SQLException { logger = LogManager.getLogger(getClass()); //logger.debug("created new connection"); connect(); checkDataSourceStatus(); } public DBHandler(DBHandler copy) { this.connection = copy.connection; } /** * Nur zur Sicherheit, falls jemand vergessen hat die DB-Verbindung zu schlieen. Sollte aber * trotzdem immer gemacht werden! */ @Override protected void finalize() throws Throwable { super.finalize(); close(); } private static BasicDataSource setupDataSource(String server, int port, String dbName, String username, String password, int maxActive, int maxIdle) { Preconditions.checkNotNull(server); Preconditions.checkNotNull(dbName); Preconditions.checkNotNull(username); BasicDataSource ds = new BasicDataSource(); ds.setDriverClassName("com.mysql.jdbc.Driver"); ds.setUsername(username); if (password.length() > 0) { ds.setPassword(password); } String url = String.format("jdbc:mysql://%s:%d/%s?useConfigs=maxPerformance&useCompression=true", server, port, dbName); ds.setUrl(url); ds.setValidationQuery("SELECT 1;"); ds.setTestWhileIdle(true); ds.setTestOnReturn(true); ds.setMaxTotal(maxActive); ds.setMaxIdle(maxIdle); ds.setRemoveAbandonedOnBorrow(true); ds.setRemoveAbandonedTimeout(60); if (Configuration.getInstance().isDeveloperMode()) { ds.setLogAbandoned(true); } sLogger.info("created new Connectionpool"); return ds; } public static void closeSource() { try { dataSource.close(); dataSource = null; Enumeration<Driver> drivers = DriverManager.getDrivers(); while (drivers.hasMoreElements()) { DriverManager.deregisterDriver(drivers.nextElement()); } } catch (SQLException e) { sLogger.error(e); } } private void connect() throws SQLException { if (dataSource == null) { throw new SQLException("Connection pool has not been initialized"); } connection = dataSource.getConnection(); } @Override public void close() { try { connection.close(); connection = null; } catch (SQLException e) { logger.debug("failed to close connection", e); } //logger.debug("closed a connection"); } public String toString() { return "Connection: " + connection; } public static void checkDataSourceStatus() { if (dataSource.getMaxTotal() - dataSource.getNumActive() <= 12) { sLogger.warn("running out of connections!"); printDataSourceStatus(); } } public static void printDataSourceStatus() { sLogger.info(String.format("MySQLConn. Idle: %d MaxIdle: %d NumActive: %d MaxActive: %d", dataSource.getNumIdle(), dataSource.getMaxIdle(), dataSource.getNumActive(), dataSource.getMaxTotal())); } public static int getNumActive() { return dataSource.getNumActive(); } public static int getMaxActive() { return dataSource.getMaxTotal(); } public static int getNumIdle() { return dataSource.getNumIdle(); } public static int getMaxIdle() { return dataSource.getMaxIdle(); } public static ConnectionStatus getConnectionsStatus() { ConnectionStatus status = new ConnectionStatus(); status.setNumActive(getNumActive()); status.setMaxActive(getMaxActive()); status.setNumIdle(getNumIdle()); status.setMaxIdle(getMaxIdle()); return status; } public static class ConnectionStatus { private int numActive; private int maxActive; private int numIdle; private int maxIdle; public int getNumActive() { return numActive; } public void setNumActive(int numActive) { this.numActive = numActive; } public int getMaxActive() { return maxActive; } public void setMaxActive(int maxActive) { this.maxActive = maxActive; } public int getNumIdle() { return numIdle; } public void setNumIdle(int numIdle) { this.numIdle = numIdle; } public int getMaxIdle() { return maxIdle; } public void setMaxIdle(int maxIdle) { this.maxIdle = maxIdle; } } }