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/*
 * 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
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/**
 * 

* This package contains two DataSources: PerUserPoolDataSource and * SharedPoolDataSource which provide a database connection pool. * Below are a couple of usage examples. One shows deployment into a JNDI system. * The other is a simple example initializing the pool using standard java code. *

* *

JNDI

* *

* Most * J2EE containers will provide some way of deploying resources into JNDI. The * method will vary among containers, but once the resource is available via * JNDI, the application can access the resource in a container independent * manner. The following example shows deployment into tomcat (catalina). *

*

In server.xml, the following would be added to the <Context> for your * webapp: *

* * * <Resource name="jdbc/bookstore" auth="Container" * type="com.frameworkset.commons.dbcp2.datasources.PerUserPoolPoolDataSource"/> * <ResourceParams name="jdbc/bookstore"> * <parameter> * <name>factory</name> * <value>com.frameworkset.commons.dbcp2.datasources.PerUserPoolDataSourceFactory</value> * </parameter> * <parameter> * <name>dataSourceName</name><value>java:comp/env/jdbc/bookstoreCPDS</value> * </parameter> * <parameter> * <name>defaultMaxTotal</name><value>30</value> * </parameter> * </ResourceParams> * * *

* In web.xml. Note that elements must be given in the order of the dtd * described in the servlet specification: *

* * * <resource-ref> * <description> * Resource reference to a factory for java.sql.Connection * instances that may be used for talking to a particular * database that is configured in the server.xml file. * </description> * <res-ref-name> * jdbc/bookstore * </res-ref-name> * <res-type> * com.frameworkset.commons.dbcp2.datasources.PerUserPoolDataSource * </res-type> * <res-auth> * Container * </res-auth> * </resource-ref> * * *

* Apache Tomcat deploys all objects configured similarly to above within the * java:comp/env namespace. So the JNDI path given for * the dataSourceName parameter is valid for a * ConnectionPoolDataSource that is deployed as given in the * cpdsadapter example *

* *

* The DataSource is now available to the application as shown * below: *

* * * * Context ctx = new InitialContext(); * DataSource ds = (DataSource) * ctx.lookup("java:comp/env/jdbc/bookstore"); * Connection con = null; * try * { * con = ds.getConnection(); * ... * use the connection * ... * } * finally * { * if (con != null) * con.close(); * } * * * *

* The reference to the DataSource could be maintained, for * multiple getConnection() requests. Or the DataSource can be * looked up in different parts of the application code. * PerUserPoolDataSourceFactory and * SharedPoolDataSourceFactory will maintain the state of the pool * between different lookups. This behavior may be different in other * implementations. *

* *

Without JNDI

* *

* Connection pooling is useful in applications regardless of whether they run * in a J2EE environment and a DataSource can be used within a * simpler environment. The example below shows SharedPoolDataSource using * DriverAdapterCPDS as the backend source, though any CPDS is applicable. *

* * * * public class Pool * { * private static DataSource ds; * * static * { * DriverAdapterCPDS cpds = new DriverAdapterCPDS(); * cpds.setDriver("org.gjt.mm.mysql.Driver"); * cpds.setUrl("jdbc:mysql://localhost:3306/bookstore"); * cpds.setUser("foo"); * cpds.setPassword(null); * * SharedPoolDataSource tds = new SharedPoolDataSource(); * tds.setConnectionPoolDataSource(cpds); * tds.setMaxTotal(10); * tds.setMaxWaitMillis(50); * * ds = tds; * } * * public static getConnection() * { * return ds.getConnection(); * } * } * * * *

* This class can then be used wherever a connection is needed: *

* * * Connection con = null; * try * { * con = Pool.getConnection(); * ... * use the connection * ... * } * finally * { * if (con != null) * con.close(); * } * */ package com.frameworkset.commons.dbcp2.datasources;




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