| /* |
| * 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. |
| */ |
| |
| /** |
| * <p> |
| * Database Connection Pool API. |
| * </p> |
| * |
| * <b>Overview in Dialog Form</b> |
| * <p> |
| * Q: How do I use the DBCP package? |
| * </p> |
| * <p> |
| * A: There are two primary ways to access the DBCP pool, as a {@link java.sql.Driver Driver}, or as a |
| * {@link javax.sql.DataSource DataSource}. You'll want to create an instance of |
| * {@link org.apache.tomcat.dbcp.dbcp2.PoolingDriver} or {@link org.apache.tomcat.dbcp.dbcp2.PoolingDataSource}. When using one |
| * of these interfaces, you can just use your JDBC objects the way you normally would. Closing a |
| * {@link java.sql.Connection} will simply return it to its pool. |
| * </p> |
| * <p> |
| * Q: But {@link org.apache.tomcat.dbcp.dbcp2.PoolingDriver PoolingDriver} and |
| * {@link org.apache.tomcat.dbcp.dbcp2.PoolingDataSource PoolingDataSource} both expect an |
| * {@link org.apache.tomcat.dbcp.pool2.ObjectPool ObjectPool} as an input. Where do I get one of those? |
| * </p> |
| * <p> |
| * A: The {@link org.apache.tomcat.dbcp.pool2.ObjectPool ObjectPool} interface is defined in Commons Pool. You can use one |
| * of the provided implementations such as {@link org.apache.tomcat.dbcp.pool2.impl.GenericObjectPool GenericObjectPool} or |
| * {@link org.apache.tomcat.dbcp.pool2.impl.SoftReferenceObjectPool SoftReferenceObjectPool} or you can create your own. |
| * </p> |
| * <p> |
| * Q: Ok, I've found an {@link org.apache.tomcat.dbcp.pool2.ObjectPool ObjectPool} implementation that I think suits my |
| * connection pooling needs. But it wants a {@link org.apache.tomcat.dbcp.pool2.PooledObjectFactory PooledObjectFactory}. |
| * What should I use for that? |
| * </p> |
| * <p> |
| * A: The DBCP package provides a class for this purpose. It's called |
| * {@link org.apache.tomcat.dbcp.dbcp2.PoolableConnectionFactory}. It implements the factory and lifecycle methods of |
| * {@link org.apache.tomcat.dbcp.pool2.PooledObjectFactory} for {@link java.sql.Connection}s. But it doesn't create the |
| * actual database {@link java.sql.Connection}s itself, it uses a {@link org.apache.tomcat.dbcp.dbcp2.ConnectionFactory} for |
| * that. The {@link org.apache.tomcat.dbcp.dbcp2.PoolableConnectionFactory} will take {@link java.sql.Connection}s created |
| * by the {@link org.apache.tomcat.dbcp.dbcp2.ConnectionFactory} and wrap them with classes that implement the pooling |
| * behaviour. |
| * </p> |
| * <p> |
| * Several implementations of {@link org.apache.tomcat.dbcp.dbcp2.ConnectionFactory} are provided--one that uses |
| * {@link java.sql.DriverManager} to create connections |
| * ({@link org.apache.tomcat.dbcp.dbcp2.DriverManagerConnectionFactory}), one that uses a {@link java.sql.Driver} to create |
| * connections ({@link org.apache.tomcat.dbcp.dbcp2.DriverConnectionFactory}), one that uses a {@link javax.sql.DataSource} |
| * to create connections ({@link org.apache.tomcat.dbcp.dbcp2.DataSourceConnectionFactory}). |
| * </p> |
| * <p> |
| * Q: I think I'm starting to get it, but can you walk me though it again? |
| * </p> |
| * <p> |
| * A: Sure. Let's assume you want to create a {@link javax.sql.DataSource} that pools {@link java.sql.Connection}s. |
| * Let's also assume that those pooled {@link java.sql.Connection}s should be obtained from the |
| * {@link java.sql.DriverManager}. You'll want to create a {@link org.apache.tomcat.dbcp.dbcp2.PoolingDataSource}. |
| * </p> |
| * <p> |
| * The {@link org.apache.tomcat.dbcp.dbcp2.PoolingDataSource} uses an underlying {@link org.apache.tomcat.dbcp.pool2.ObjectPool} |
| * to create and store its {@link java.sql.Connection}. |
| * </p> |
| * <p> |
| * To create a {@link org.apache.tomcat.dbcp.pool2.ObjectPool}, you'll need a |
| * {@link org.apache.tomcat.dbcp.pool2.PooledObjectFactory} that creates the actual {@link java.sql.Connection}s. That's |
| * what {@link org.apache.tomcat.dbcp.dbcp2.PoolableConnectionFactory} is for. |
| * </p> |
| * <p> |
| * To create the {@link org.apache.tomcat.dbcp.dbcp2.PoolableConnectionFactory}, you'll need at least two things: |
| * </p> |
| * <ol> |
| * <li>A {@link org.apache.tomcat.dbcp.dbcp2.ConnectionFactory} from which the actual database {@link java.sql.Connection}s |
| * will be obtained.</li> |
| * <li>An empty and factory-less {@link org.apache.tomcat.dbcp.pool2.ObjectPool} in which the {@link java.sql.Connection}s |
| * will be stored. <br> |
| * When you pass an {@link org.apache.tomcat.dbcp.pool2.ObjectPool} into the |
| * {@link org.apache.tomcat.dbcp.dbcp2.PoolableConnectionFactory}, it will automatically register itself as the |
| * {@link org.apache.tomcat.dbcp.pool2.PooledObjectFactory} for that pool.</li> |
| * </ol> |
| * <p> |
| * In code, that might look like this: |
| * </p> |
| * |
| * <pre> |
| * GenericObjectPool connectionPool = new GenericObjectPool(null); |
| * ConnectionFactory connectionFactory = new DriverManagerConnectionFactory("jdbc:some:connect:string", "userName", |
| * "password"); |
| * PoolableConnectionFactory poolableConnectionFactory = new PoolableConnectionFactory(connectionFactory, |
| * connectionPool, null, null, false, true); |
| * PoolingDataSource dataSource = new PoolingDataSource(connectionPool); |
| * </pre> |
| * <p> |
| * To create a {@link org.apache.tomcat.dbcp.dbcp2.PoolingDriver}, we do the same thing, except that instead of creating a |
| * {@link javax.sql.DataSource} on the last line, we create a {@link org.apache.tomcat.dbcp.dbcp2.PoolingDriver}, and |
| * register the {@code connectionPool} with it. E.g.,: |
| * </p> |
| * |
| * <pre> |
| * GenericObjectPool connectionPool = new GenericObjectPool(null); |
| * ConnectionFactory connectionFactory = new DriverManagerConnectionFactory("jdbc:some:connect:string", "userName", |
| * "password"); |
| * PoolableConnectionFactory poolableConnectionFactory = new PoolableConnectionFactory(connectionFactory, |
| * connectionPool, null, null, false, true); |
| * PoolingDriver driver = new PoolingDriver(); |
| * driver.registerPool("example", connectionPool); |
| * </pre> |
| * <p> |
| * Since the {@link org.apache.tomcat.dbcp.dbcp2.PoolingDriver} registers itself with the {@link java.sql.DriverManager} |
| * when it is created, now you can just go to the {@link java.sql.DriverManager} to create your |
| * {@link java.sql.Connection}s, like you normally would: |
| * </p> |
| * |
| * <pre> |
| * Connection conn = DriverManager.getConnection("jdbc:apache:commons:dbcp:example"); |
| * </pre> |
| */ |
| package org.apache.tomcat.dbcp.dbcp2; |
