Java tutorial
/** * Copyright (C) 2010-2012 the original author or authors. * * Licensed 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 com.googlecode.flyway.core.util.jdbc; import com.googlecode.flyway.core.exception.FlywayException; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import javax.sql.DataSource; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; /** * Utility class for dealing with jdbc connections. */ public class JdbcUtils { private static final Log LOG = LogFactory.getLog(JdbcUtils.class); /** * Prevents instantiation. */ private JdbcUtils() { //Do nothing } /** * Opens a new connection from this dataSource. * * @param dataSource The dataSource to obtain the connection from. * @return The new connection. * @throws FlywayException when the connection could not be opened. */ public static Connection openConnection(DataSource dataSource) throws FlywayException { try { Connection connection = dataSource.getConnection(); if (connection == null) { throw new FlywayException("Unable to obtain Jdbc connection from DataSource"); } return connection; } catch (SQLException e) { throw new FlywayException("Unable to obtain Jdbc connection from DataSource", e); } } /** * Safely closes this connection. This method never fails. * * @param connection The connection to close. */ public static void closeConnection(Connection connection) { if (connection == null) { return; } try { connection.close(); } catch (SQLException e) { LOG.error("Error while closing Jdbc connection", e); } } /** * Safely closes this statement. This method never fails. * * @param statement The statement to close. */ public static void closeStatement(Statement statement) { if (statement == null) { return; } try { statement.close(); } catch (SQLException e) { LOG.error("Error while closing Jdbc statement", e); } } /** * Safely closes this resultSet. This method never fails. * * @param resultSet The resultSet to close. */ public static void closeResultSet(ResultSet resultSet) { if (resultSet == null) { return; } try { resultSet.close(); } catch (SQLException e) { LOG.error("Error while closing Jdbc resultSet", e); } } }