Servlets, JDBC, and Inter-Servlet Communications - Developing Java Servlets - page 114

The initializePool() method first loads the JDBC driver. It then creates size number of
Connection objects. For each Connection object created, it creates a PooledConnection
object, passing it the Connection in the constructor. Finally, it adds the newly create
PooledConnection object to the pool.

The PooledConnection object simply wraps a JDBC Connection object in a class that holds
the connection and a flag that determines whether the connection is in use or not. It is listed in
Listing 7.9.

L ISTING 7.9

PooledConnection.java

package ConnectionPool;

import java.sql.*;

public class PooledConnection {

// Real JDBC Connection
private Connection connection = null;
// boolean flag used to determine if connection is in use
private boolean inuse = false;

// Constructor that takes the passed in JDBC Connection
// and stores it in the connection attribute.
public PooledConnection(Connection value) {

if ( value != null ) {

connection = value;

}

}

// Returns a reference to the JDBC Connection
public Connection getConnection() {

// get the JDBC Connection
return connection;

}

// Set the status of the PooledConnection.
public void setInUse(boolean value) {

inuse = value;

}