// Copyright (c) 1998 Thomas E. Davis

import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Connection;

public class JDBCConnectionPool extends ObjectPool
{
    private String dsn, usr, pwd;
    
    public JDBCConnectionPool( String driver, String dsn, String usr, String pwd )
    {
        try
        {
            Class.forName( driver ).newInstance();
        }
        catch( Exception e )
        {
            e.printStackTrace();
        }
        this.dsn = dsn;
        this.usr = usr;
        this.pwd = pwd;
    }
    
    Object create() throws SQLException
    {
        return( DriverManager.getConnection( dsn, usr, pwd ) );
    }
    
    boolean validate( Object o )
    {
        try
        {
            return( ! ( ( Connection ) o ).isClosed() );
        }
        catch( SQLException e )
        {
            e.printStackTrace();
            return false;
        }
    }
    
    void expire( Object o )
    {
        try
        {
            ( ( Connection ) o ).close();
        }
        catch( SQLException e )
        {
            e.printStackTrace();
        }
    }
    
    public Connection borrowConnection() throws SQLException
    {
        try
        {
            return( ( Connection ) super.checkOut() );
        }
        catch( Exception e )
        {
            throw( (SQLException) e );
        }
    }
    
    public void returnConnection( Connection c )
    {
        super.checkIn( c );
    }
}