导入包

关于c3p0配置

    
    	
     			 
      
       root
      		
      
       339446
      		
      
       com.mysql.jdbc.Driver
      		
      
       jdbc:mysql:///web20?useSSL=false
      	
      
    

关于封装工具类

package com.itheima.utils;import java.sql.Connection;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import javax.sql.DataSource;import com.mchange.v2.c3p0.ComboPooledDataSource;public class DataSourceUtils {	private static DataSource dataSource = new ComboPooledDataSource();	private static ThreadLocal
    
      tl = new ThreadLocal
     
      ();	// 直接可以获取一个连接池	public static DataSource getDataSource() {		return dataSource;	}		public static Connection getConnection() throws SQLException{		return dataSource.getConnection();	}	// 获取连接对象	public static Connection getCurrentConnection() throws SQLException {		Connection con = tl.get();		if (con == null) {			con = dataSource.getConnection();			tl.set(con);		}		return con;	}	// 开启事务	public static void startTransaction() throws SQLException {		Connection con = getCurrentConnection();		if (con != null) {			con.setAutoCommit(false);		}	}	// 事务回滚	public static void rollback() throws SQLException {		Connection con = getCurrentConnection();		if (con != null) {			con.rollback();		}	}	// 提交并且 关闭资源及从ThreadLocall中释放	public static void commitAndRelease() throws SQLException {		Connection con = getCurrentConnection();		if (con != null) {			con.commit(); // 事务提交			con.close();// 关闭资源			tl.remove();// 从线程绑定中移除		}	}	// 关闭资源方法	public static void closeConnection() throws SQLException {		Connection con = getCurrentConnection();		if (con != null) {			con.close();		}	}	public static void closeStatement(Statement st) throws SQLException {		if (st != null) {			st.close();		}	}	public static void closeResultSet(ResultSet rs) throws SQLException {		if (rs != null) {			rs.close();		}	}}
     
    

使用案例

public List
    
      findAllProduct() throws SQLException {		return new QueryRunner(DataSourceUtils.getDataSource()).query("select * from product", new BeanListHandler
     
      (Product.class));	}