监控Proxool连接池的活动连接变化情况

/**//*
*@author 我为J狂 建立日期 2007-4-18
*
*/
package net.blogjava.lzqdiy;

import java.net.URL;
import java.sql.*;
import org.logicalcobwebs.proxool.ProxoolException;
import org.logicalcobwebs.proxool.ProxoolFacade;
import org.logicalcobwebs.proxool.configuration.JAXPConfigurator;
import org.logicalcobwebs.proxool.admin.SnapshotIF;

public class DBConnection
{

    private static boolean initialized = false;

    private static int activeCount = 0;

    public static Connection getConnection() throws SQLException
    {
        Connection connection = null;
        if (!initialized)
        {

            init();
        }

        connection = DriverManager.getConnection("proxool.Develop");
        try
        {
            SnapshotIF snapshot = ProxoolFacade.getSnapshot("Develop", true);
            int curActiveCount = snapshot.getActiveConnectionCount();// 获得活动连接数
            int availableCount = snapshot.getAvailableConnectionCount();// 获得可得到的连接数
            int maxCount = snapshot.getMaximumConnectionCount();// 获得总连接数
            if (curActiveCount != activeCount)// 当活动连接数变化时输出信息
            {
                System.out.println("----------------------------------");
                System.out
                        .println(curActiveCount + "(active)  " + availableCount
                                + "(available)  " + maxCount + "(max)");
                System.out.println("----------------------------------");
                activeCount = curActiveCount;
            }

        } catch (ProxoolException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        if (connection != null)
        {

            return connection;
        } else
        {
            throw new NullPointerException(
                    "Didn't get connection, which probably means that no Driver accepted the URL");
        }

    }

    private static void init()
    {
        String fileName = "proxool.xml";
        URL resourceURL = null;
        try
        {
            if (Thread.currentThread().getContextClassLoader() != null)
            {
                resourceURL = Thread.currentThread().getContextClassLoader()
                        .getResource(fileName);
            }

            if (resourceURL == null)
            {
                resourceURL = DBConnection.class.getClassLoader().getResource(
                        fileName);
            }

            JAXPConfigurator.configure(resourceURL.getFile(), false);
            Class.forName("org.logicalcobwebs.proxool.ProxoolDriver");
        } catch (ClassNotFoundException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (ProxoolException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        initialized = true;
    }
}