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);
    }
}