Java tutorial
/******************************************************************************* * This file is part of OpenNMS(R). * * Copyright (C) 2012 The OpenNMS Group, Inc. * OpenNMS(R) is Copyright (C) 1999-2012 The OpenNMS Group, Inc. * * OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc. * * OpenNMS(R) 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. * * OpenNMS(R) 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 OpenNMS(R). If not, see: * http://www.gnu.org/licenses/ * * For more information contact: * OpenNMS(R) Licensing <license@opennms.org> * http://www.opennms.org/ * http://www.opennms.com/ *******************************************************************************/ package org.opennms.core.db; import java.beans.PropertyVetoException; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.io.PrintWriter; import java.lang.reflect.Constructor; import java.sql.Connection; import java.sql.SQLException; import java.sql.SQLFeatureNotSupportedException; import java.util.LinkedList; import java.util.List; import java.util.Map; import java.util.concurrent.ConcurrentHashMap; import javax.sql.DataSource; import org.apache.commons.io.IOUtils; import org.exolab.castor.xml.MarshalException; import org.exolab.castor.xml.ValidationException; import org.opennms.core.utils.ConfigFileConstants; import org.opennms.core.xml.CastorUtils; import org.opennms.netmgt.config.opennmsDataSources.ConnectionPool; import org.opennms.netmgt.config.opennmsDataSources.DataSourceConfiguration; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.jdbc.datasource.LazyConnectionDataSourceProxy; /** * <p> * This is the singleton class used to load the OpenNMS database configuration * from the opennms-database.xml. This provides convenience methods to create * database connections to the database configured in this default xml * </p> * * <p> * <strong>Note: </strong>Users of this class should make sure the * <em>init()</em> is called before calling any other method to ensure the * config is loaded before accessing other convenience methods * </p> * * @author <a href="mailto:weave@oculan.com">Brian Weaver </a> */ public final class DataSourceFactory implements DataSource { private static final Logger LOG = LoggerFactory.getLogger(DataSourceFactory.class); private static final Class<?> DEFAULT_FACTORY_CLASS = C3P0ConnectionFactory.class; /** * The singleton instance of this factory */ private static DataSource m_singleton = null; private static final Map<String, DataSource> m_dataSources = new ConcurrentHashMap<String, DataSource>(); private static final List<Runnable> m_closers = new LinkedList<Runnable>(); /** * Load the config from the default config file and create the singleton * instance of this factory. * * @exception java.io.IOException * Thrown if the specified config file cannot be read * @exception org.exolab.castor.xml.MarshalException * Thrown if the file does not conform to the schema. * @exception org.exolab.castor.xml.ValidationException * Thrown if the contents do not match the required schema. * @throws java.sql.SQLException if any. * @throws java.beans.PropertyVetoException if any. * @throws java.io.IOException if any. * @throws org.exolab.castor.xml.MarshalException if any. * @throws org.exolab.castor.xml.ValidationException if any. * @throws java.lang.ClassNotFoundException if any. */ public static synchronized void init() throws IOException, MarshalException, ValidationException, ClassNotFoundException, PropertyVetoException, SQLException { if (!isLoaded("opennms")) { init("opennms"); } } /** * <p>init</p> * * @param dsName a {@link java.lang.String} object. * @throws java.io.IOException if any. * @throws org.exolab.castor.xml.MarshalException if any. * @throws org.exolab.castor.xml.ValidationException if any. * @throws java.lang.ClassNotFoundException if any. * @throws java.beans.PropertyVetoException if any. * @throws java.sql.SQLException if any. */ public static synchronized void init(final String dsName) throws IOException, MarshalException, ValidationException, ClassNotFoundException, PropertyVetoException, SQLException { if (isLoaded(dsName)) { // init already called - return // to reload, reload() will need to be called return; } String factoryClass = null; final File cfgFile = ConfigFileConstants.getFile(ConfigFileConstants.OPENNMS_DATASOURCE_CONFIG_FILE_NAME); DataSourceConfiguration dsc = null; ConnectionPool connectionPool = null; FileInputStream fileInputStream = null; try { fileInputStream = new FileInputStream(cfgFile); dsc = CastorUtils.unmarshal(DataSourceConfiguration.class, fileInputStream); connectionPool = dsc.getConnectionPool(); if (connectionPool != null) { factoryClass = connectionPool.getFactory(); } } finally { IOUtils.closeQuietly(fileInputStream); } final String configPath = cfgFile.getPath(); ClosableDataSource dataSource = null; final String defaultClassName = DEFAULT_FACTORY_CLASS.getName(); try { final Class<?> clazz = Class.forName(factoryClass); final Constructor<?> constructor = clazz.getConstructor(new Class<?>[] { String.class, String.class }); dataSource = (ClosableDataSource) constructor.newInstance(new Object[] { configPath, dsName }); } catch (final Throwable t) { LOG.debug("Unable to load {}, falling back to the default dataSource ({})", factoryClass, defaultClassName, t); try { final Constructor<?> constructor = ((Class<?>) DEFAULT_FACTORY_CLASS) .getConstructor(new Class<?>[] { String.class, String.class }); dataSource = (ClosableDataSource) constructor.newInstance(new Object[] { configPath, dsName }); } catch (final Throwable cause) { LOG.error("Unable to load {}.", DEFAULT_FACTORY_CLASS.getName(), cause); throw new SQLException("Unable to load " + defaultClassName + ".", cause); } } final ClosableDataSource runnableDs = dataSource; m_closers.add(new Runnable() { @Override public void run() { try { runnableDs.close(); } catch (final Throwable cause) { LOG.info("Unable to close datasource {}.", dsName, cause); } } }); if (connectionPool != null) { dataSource.setIdleTimeout(connectionPool.getIdleTimeout()); dataSource.setLoginTimeout(connectionPool.getLoginTimeout()); dataSource.setMinPool(connectionPool.getMinPool()); dataSource.setMaxPool(connectionPool.getMaxPool()); dataSource.setMaxSize(connectionPool.getMaxSize()); } // Springframework provided proxies that make working with transactions much easier final LazyConnectionDataSourceProxy lazyProxy = new LazyConnectionDataSourceProxy(dataSource); setInstance(dsName, lazyProxy); } private static synchronized boolean isLoaded(final String dsName) { return m_dataSources.containsKey(dsName); } /** * <p> * Return the singleton instance of this factory. This is the instance of * the factory that was last created when the <code> * init</code> or * <code>reload</code> method was invoked. The instance will not change * unless a <code>reload</code> method is invoked. * </p> * * @return The current factory instance. * @throws java.lang.IllegalStateException * Thrown if the factory has not yet been initialized. */ public static DataSource getInstance() { return getInstance("opennms"); } /** * <p>getInstance</p> * * @param name a {@link java.lang.String} object. * @return a {@link javax.sql.DataSource} object. */ public static DataSource getInstance(final String name) { final DataSource dataSource = getDataSource(name); if (dataSource == null) { throw new IllegalArgumentException( "Unable to locate data source named " + name + ". Does this need to be init'd?"); } else { return dataSource; } } /** * Return a new database connection to the database configured in the * <tt>opennms-database.xml</tt>. The database connection is not managed * by the factory and must be release by the caller by using the * <code>close</code> method. * * @return a new database connection to the database configured in the * <tt>opennms-database.xml</tt> * @throws java.sql.SQLException * Thrown if there is an error opening the connection to the * database. */ @Override public Connection getConnection() throws SQLException { return getConnection("opennms"); } /** * <p>getConnection</p> * * @param dsName a {@link java.lang.String} object. * @return a {@link java.sql.Connection} object. * @throws java.sql.SQLException if any. */ public Connection getConnection(final String dsName) throws SQLException { return getDataSource(dsName).getConnection(); } /** * <p>setInstance</p> * * @param singleton a {@link javax.sql.DataSource} object. */ public static void setInstance(final DataSource singleton) { m_singleton = singleton; setInstance("opennms", singleton); } /** * <p>setInstance</p> * * @param dsName a {@link java.lang.String} object. * @param singleton a {@link javax.sql.DataSource} object. */ public static synchronized void setInstance(final String dsName, final DataSource singleton) { m_dataSources.put(dsName, singleton); } /** * Return the datasource configured for the database * * @return the datasource configured for the database */ public static DataSource getDataSource() { return getDataSource("opennms"); } /** * <p>getDataSource</p> * * @param dsName a {@link java.lang.String} object. * @return a {@link javax.sql.DataSource} object. */ public static synchronized DataSource getDataSource(final String dsName) { return m_dataSources.get(dsName); } /** {@inheritDoc} */ @Override public Connection getConnection(final String username, final String password) throws SQLException { return getConnection(); } /** * <p>getLogWriter</p> * * @return a {@link java.io.PrintWriter} object. * @throws java.sql.SQLException if any. */ @Override public PrintWriter getLogWriter() throws SQLException { return m_singleton.getLogWriter(); } /** * <p>getLogWriter</p> * * @param dsName a {@link java.lang.String} object. * @return a {@link java.io.PrintWriter} object. * @throws java.sql.SQLException if any. */ public PrintWriter getLogWriter(final String dsName) throws SQLException { return getDataSource(dsName).getLogWriter(); } /** {@inheritDoc} */ @Override public void setLogWriter(final PrintWriter out) throws SQLException { setLogWriter("opennms", out); } /** * <p>setLogWriter</p> * * @param dsName a {@link java.lang.String} object. * @param out a {@link java.io.PrintWriter} object. * @throws java.sql.SQLException if any. */ public void setLogWriter(final String dsName, final PrintWriter out) throws SQLException { getDataSource(dsName).setLogWriter(out); } /** {@inheritDoc} */ @Override public void setLoginTimeout(final int seconds) throws SQLException { setLoginTimeout("opennms", seconds); } /** * <p>setLoginTimeout</p> * * @param dsName a {@link java.lang.String} object. * @param seconds a int. * @throws java.sql.SQLException if any. */ public void setLoginTimeout(final String dsName, final int seconds) throws SQLException { getDataSource(dsName).setLoginTimeout(seconds); } /** * <p>getLoginTimeout</p> * * @return a int. * @throws java.sql.SQLException if any. */ @Override public int getLoginTimeout() throws SQLException { return getLoginTimeout("opennms"); } /** * <p>getLoginTimeout</p> * * @param dsName a {@link java.lang.String} object. * @return a int. * @throws java.sql.SQLException if any. */ public int getLoginTimeout(final String dsName) throws SQLException { return getDataSource(dsName).getLoginTimeout(); } /** {@inheritDoc} */ public java.util.logging.Logger getParentLogger() throws SQLFeatureNotSupportedException { throw new SQLFeatureNotSupportedException("getParentLogger not supported"); } /** * <p>close</p> * * @throws java.sql.SQLException if any. */ public static synchronized void close() throws SQLException { for (Runnable closer : m_closers) { closer.run(); } m_closers.clear(); m_dataSources.clear(); } /** * <p>unwrap</p> * * @param iface a {@link java.lang.Class} object. * @param <T> a T object. * @return a T object. * @throws java.sql.SQLException if any. */ @Override public <T> T unwrap(final Class<T> iface) throws SQLException { return null; //TODO } /** * <p>isWrapperFor</p> * * @param iface a {@link java.lang.Class} object. * @return a boolean. * @throws java.sql.SQLException if any. */ @Override public boolean isWrapperFor(final Class<?> iface) throws SQLException { return false; //TODO } }