c3p0数据库连接池问题

由于以前做的项目没用mysql是用自己的连接池. 新启一个工程用到mysql,mysql对于连接超过8小时,就会断开连接. 在网上查了下,说c3p0可以解决该问题. 找了点资料,配置后写代码测试,发觉c3p0也并没有提高效率,难道是我代码写错了. 因为c3p0每次都得释放连接,感觉用不用作用不太大.

import java.beans.PropertyVetoException;
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Properties;

import javax.sql.rowset.CachedRowSet;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import com.sun.rowset.CachedRowSetImpl;
import com.zhongwei.connectionpool.ConnectionPool;


public class ConnectionManager
{
    private static ConnectionManager instance;
    
    private static ComboPooledDataSource dataSource;
    
    private ConnectionManager() throws IOException, SQLException,
            PropertyVetoException
    {
        
        Properties p = new Properties();
        
        p.load(this.getClass().getResourceAsStream("c3p0.properties"));
        
        dataSource = new ComboPooledDataSource();
        
        dataSource.setProperties(p);
        
        System.out.println(p.getProperty("password"));
        
        dataSource.setUser(p.getProperty("user"));
        dataSource.setPassword(p.getProperty("password"));
        dataSource.setJdbcUrl(p.getProperty("jdbcUrl"));
        dataSource.setDriverClass(p.getProperty("driverClass"));
        dataSource.setInitialPoolSize(Integer.valueOf(p.getProperty("initialPoolSize")));
        dataSource.setMinPoolSize(Integer.valueOf(p.getProperty("minPoolSize")));
        dataSource.setMaxPoolSize(Integer.valueOf(p.getProperty("maxPoolSize")));
        dataSource.setMaxStatements(Integer.valueOf(p.getProperty("maxStatements")));
        dataSource.setMaxIdleTime(Integer.valueOf(p.getProperty("maxIdleTime")));
        dataSource.setPreferredTestQuery(p.getProperty("preferredTestQuery"));
        dataSource.setIdleConnectionTestPeriod(Integer.valueOf(p.getProperty("idleConnectionTestPeriod")));
        dataSource.setTestConnectionOnCheckout(Boolean.valueOf(p.getProperty("testConnectionOnCheckout")));
        dataSource.setTestConnectionOnCheckin(Boolean.valueOf(p.getProperty("testConnectionOnCheckin")));
        dataSource.setAcquireIncrement(Integer.valueOf(p.getProperty("acquireIncrement")));
        dataSource.setAcquireRetryAttempts(Integer.valueOf(p.getProperty("acquireRetryAttempts")));
        dataSource.setAcquireRetryDelay(Integer.valueOf(p.getProperty("acquireRetryDelay")));
        dataSource.setAutomaticTestTable(p.getProperty("automaticTestTable"));
        dataSource.setCheckoutTimeout(Integer.valueOf(p.getProperty("checkoutTimeout")));
        dataSource.setAutoCommitOnClose(Boolean.valueOf(p.getProperty("autoCommitOnClose")));
        
    }
    
    public static final ConnectionManager getInstance()
    {
        if (instance == null)
        {
            try
            {
                instance = new ConnectionManager();
            }
            catch (Exception e)
            {
                e.printStackTrace();
            }
        }
        return instance;
    }
    
    public synchronized final Connection getConnection()
    {
        Connection connection = null;
        
        try
        {
            connection = dataSource.getConnection();
            
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
        return connection;
    }
    
 
    public static void main(String[] args) throws Exception
    {
         System.out.println("开始使用连接池...");
      
         PreparedStatement pst = null;
         
         for(int i=0;i<10;i++)
         {
             long beginTime = System.currentTimeMillis();
             
             ConnectionManager inManager = ConnectionManager.getInstance();
             
             Connection conn = inManager.getConnection(); 
             
             try
             {
                 pst = conn.prepareStatement("select * from tb_smsqueue");
                 
                 

                     ResultSet rs = pst.executeQuery();
                     rs.close();
             }
             catch (Exception e)
             {
                 e.printStackTrace();
             }
             finally
             {
                 try
                 {
                     //这里每次要释放连接,用不用连接池有什么作用?
                     if(pst != null)
                     {
                         pst.close();
                         conn.close();
                     }
                 }
                 catch (Exception e)
                 {
                     e.printStackTrace();
                 }
             }
             long endTime = System.currentTimeMillis();
             System.out.println("第" + (i + 1) + "次执行花费时间为:" + (endTime - beginTime));
             
         }
}

properties就不贴出来了