自定义jdbc

package com.util.jdbc;



import java.sql.Connection;

import java.sql.SQLException;

import java.util.ArrayList;

import java.util.List;



import com.alibaba.druid.pool.DruidDataSource;

/**

 * JDBC封装类

 * @author DC

 *

 */

public class JDBCUtils{

    private static DruidDataSource dataSource  = new DruidDataSource();

    //声明线程共享变量

    public static ThreadLocal<Connection> container = new ThreadLocal<Connection>();

    //配置说明，参考官方网址

    //http://blog.163.com/hongwei_benbear/blog/static/1183952912013518405588/

    static{

        dataSource.setUrl("jdbc:mysql://182.92.222.140:3306/idotest?useUnicode=true&characterEncoding=UTF-8");

        dataSource.setUsername("");//用户名

        dataSource.setPassword("");//密码

        dataSource.setInitialSize(2);

        dataSource.setMaxActive(20);

        dataSource.setMinIdle(0);

        dataSource.setMaxWait(60000);

        dataSource.setValidationQuery("SELECT 1");

        dataSource.setTestOnBorrow(false);

        dataSource.setTestWhileIdle(true);

        dataSource.setPoolPreparedStatements(false);

    }

    //禁止实体化该类

    private JDBCUtils() {}

    /**

     * 获取数据连接

     * @return

     */

    public static Connection connStart(boolean start){

        Connection conn =container.get();

        try{

            if(conn!=null){

                System.out.println(Thread.currentThread().getName()+"从map缓存中取得连接,Hashcode="+conn.hashCode());

            }else{

                System.out.println(Thread.currentThread().getName()+"从连接池中得到连接");

                conn = dataSource.getConnection();

                container.set(conn);

            }

            if(start){

                conn.setAutoCommit(false);//开启事务,默认事务级别为TRANSACTION_REPEATABLE_READ（4）

            }

        }catch(Exception e){

            System.out.println("连接获取失败");

            e.printStackTrace();

        }

        return conn;

    }

    /***关闭连接*/

    public static void connEnd(boolean end){

        Connection conn=container.get();

        if(conn!=null){

            try{

                if(end){

                    conn.commit();

                    conn.setAutoCommit(true);

                }

            }catch(Exception e){

                System.out.println("事物提交异常");

                try {

                    if(end){

                        conn.rollback();

                        System.out.println(Thread.currentThread().getName()+"事务已回滚.....hashcode+"+conn.hashCode());

                    }

                } catch (Exception e1) {

                    System.out.println("事物回滚异常");

                    e1.printStackTrace();

                }

                e.printStackTrace();

            }finally{

                try {

                    conn.close();

                    System.out.println(Thread.currentThread().getName()+"连接关闭");

                    container.remove();//从当前线程移除连接切记

                    System.out.println(Thread.currentThread().getName()+"成功移除连接。。。。");

                } catch (Exception e2) {

                    System.out.println("关闭连接异常，或者是移除缓存中的连接出错..............");

                    e2.printStackTrace();

                }

            }

        }else{

            System.out.println("关闭连接时，连接为空");

        }

    }

    public void aa(List<Integer> a,int b){

        a.set(0, 2);

        b=2;

    }

    //简单使用方式

    public static void main(String[] args) throws SQLException {

        JDBCUtils j = new JDBCUtils();

        List<Integer> a = new ArrayList<Integer>();

        a.add(1);

        int b =1;

        j.aa(a,b);

        System.out.println(a.get(0));

        System.out.println(b);

    }

}