Java/Apache Common/Connection Pool

Basic DataSource Example

   <source lang="java">

import java.sql.Connection; import org.apache.rumons.dbcp.BasicDataSource; public class BasicDataSourceExample {

 public static void main(String args[]) throws Exception {
   BasicDataSource bds = new BasicDataSource();
   bds.setDriverClassName("com.mysql.jdbc.Driver");
   bds.setUrl("jdbc:mysql://localhost/commons");
   bds.setUsername("root");
   bds.setPassword("");

// bds.setInitialSize(5);

   Connection connection = bds.getConnection();
   System.err.println(connection);
   connection.close();
 }

}

      </source>
   
  
 
  

Connection Pool Basics

   <source lang="java">

import java.sql.Connection; import java.util.Properties; import java.sql.PreparedStatement; import org.apache.rumons.dbcp.ConnectionFactory; import org.apache.rumons.dbcp.PoolingDriver; import org.apache.rumons.dbcp.PoolingDataSource; import org.apache.rumons.dbcp.DriverConnectionFactory; import org.apache.rumons.dbcp.PoolableConnectionFactory; import org.apache.rumons.dbcp.DriverManagerConnectionFactory; import org.apache.rumons.pool.impl.GenericObjectPool; import org.apache.rumons.pool.KeyedObjectPoolFactory; import org.apache.rumons.pool.impl.GenericKeyedObjectPoolFactory; public class ConnectionPoolBasics {

 public static void main(String args[]) throws Exception {
   GenericObjectPool gPool = new GenericObjectPool();
   /*Class.forName("com.mysql.jdbc.Driver");
   DriverManagerConnectionFactory cf =
     new DriverManagerConnectionFactory(
       "jdbc:mysql://localhost/commons", "root", "");*/
   Properties props = new Properties();
   props.setProperty("Username", "root");
   props.setProperty("Password", "");
   ConnectionFactory cf =
     new DriverConnectionFactory(new com.mysql.jdbc.Driver(),
                                 "jdbc:mysql://localhost/commons",
                   props);

   KeyedObjectPoolFactory kopf =new GenericKeyedObjectPoolFactory(null, 8);
   PoolableConnectionFactory pcf =  new PoolableConnectionFactory(cf,
                                   gPool,
                                   kopf,
                                   null,
                                   false,
                                   true);

   for(int i = 0; i < 5; i++) {
     gPool.addObject();
   }
   // PoolingDataSource pds = new PoolingDataSource(gPool);
   PoolingDriver pd = new PoolingDriver();
   pd.registerPool("example", gPool);
   for(int i = 0; i < 5; i++) {
     gPool.addObject();
   }
   Connection conn = java.sql.DriverManager.getConnection("jdbc:apache:commons:dbcp:example");
   System.err.println("Connection: " + conn ); //": Delegate: " + ((org.apache.rumons.dbcp.PoolingConnection)conn).getDelegate());
   // do some work with the connection
   PreparedStatement ps = conn.prepareStatement("Select * from customer where id = ?");
   System.err.println("Active: " + gPool.getNumActive() + ", Idle: " + gPool.getNumIdle());
   conn.close();
   System.err.println("Active: " + gPool.getNumActive() + ", Idle: " + gPool.getNumIdle());
 }

}

      </source>
   
  
 
  

Database connection pool demo

   <source lang="java">

import org.apache.rumons.pool.impl.GenericObjectPool; import org.apache.rumons.dbcp.*; import java.sql.*;

public class DBCPDemo{

 public static void main(String args[]) throws Exception{
   // create a generic pool
   GenericObjectPool pool = new GenericObjectPool(null);
   // use the connection factory which will wraped by
   // the PoolableConnectionFactory
   DriverManagerConnectionFactory cf =  new DriverManagerConnectionFactory(
                                           "jdbc:jtds:sqlserver://myserver:1433/tandem", 
                                           "user", 
                                           "pass");
   PoolableConnectionFactory pcf =  new PoolableConnectionFactory(cf, pool, null, "SELECT * FROM mysql.db", false, true);
   // register our pool and give it a name
   new PoolingDriver().registerPool("myPool", pool);
   // get a connection and test it
       Connection conn = DriverManager.getConnection("jdbc:apache:commons:dbcp:myPool");
       // now we can use this pool the way we want.
       System.err.println("Are we connected? " + !conn.isClosed());
       System.err.println("Idle Connections: " + pool.getNumIdle() + ", out of " + pool.getNumActive());
 }

}

      </source>