Java tutorial
/* * 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.teradata.tempto.internal.query; import com.teradata.tempto.query.JdbcConnectivityParamsState; import org.apache.commons.dbcp2.BasicDataSource; import javax.sql.DataSource; import java.io.File; import java.net.MalformedURLException; import java.net.URL; import java.net.URLClassLoader; import java.sql.Connection; import java.sql.Driver; import java.sql.SQLException; import static java.sql.DriverManager.getConnection; public final class JdbcUtils { public static void registerDriver(JdbcConnectivityParamsState jdbcParamsState) { try { Class.forName(jdbcParamsState.driverClass); } catch (ClassNotFoundException e) { throw new RuntimeException("Could not load jdbc driver class: " + jdbcParamsState.driverClass, e); } } public static DataSource dataSource(JdbcConnectivityParamsState jdbcParamsState) { if (jdbcParamsState.pooling) { return createPoolingDataSource(jdbcParamsState); } else { return createNonPoolingDataSource(jdbcParamsState); } } private static DataSource createPoolingDataSource(JdbcConnectivityParamsState jdbcParamsState) { BasicDataSource dataSource = new BasicDataSource(); dataSource.setDriverClassName(jdbcParamsState.driverClass); dataSource.setUrl(jdbcParamsState.url); dataSource.setUsername(jdbcParamsState.user); dataSource.setPassword(jdbcParamsState.password); dataSource.setDriverClassLoader(getDriverClassLoader(jdbcParamsState)); return dataSource; } private static DataSource createNonPoolingDataSource(JdbcConnectivityParamsState jdbcParamsState) { return new NonPoolingJdbcDataSource(jdbcParamsState, getDatabaseDriver(jdbcParamsState)); } private static Driver getDatabaseDriver(JdbcConnectivityParamsState jdbcParamsState) { try { Class<?> driverClass = Class.forName(jdbcParamsState.driverClass, true, getDriverClassLoader(jdbcParamsState)); return (Driver) driverClass.newInstance(); } catch (ClassNotFoundException | InstantiationException | IllegalAccessException e) { throw new RuntimeException("could not create JDBC Driver for connection " + jdbcParamsState.getName(), e); } } private static ClassLoader getDriverClassLoader(JdbcConnectivityParamsState jdbcParamsState) { try { ClassLoader myClassLoader = JdbcUtils.class.getClassLoader(); if (!jdbcParamsState.jar.isPresent()) { return myClassLoader; } URL jarURL = new File(jdbcParamsState.jar.get()).toURL(); return URLClassLoader.newInstance(new URL[] { jarURL }, myClassLoader); } catch (MalformedURLException e) { throw new RuntimeException("could not create classloader for file" + jdbcParamsState.jar.get(), e); } } public static Connection connection(JdbcConnectivityParamsState jdbcParamsState) throws SQLException { return getConnection(jdbcParamsState.url, jdbcParamsState.user, jdbcParamsState.password); } private JdbcUtils() { } }