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封裝類 * @author DC * */public class JDBCUtils{    PRivate static DruidDataSource dataSource  = new DruidDataSource();    //聲明線程共享變量    public static ThreadLocal<Connection> container = new ThreadLocal<Connection>();    //配置說明，參考官方網址    //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("");//用戶名        dataSource.setPassWord("");//密碼        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);    }    //禁止實體化該類    private JDBCUtils() {}    /**     * 獲取數據連接     * @return     */    public static Connection connStart(boolean start){        Connection conn =container.get();        try{            if(conn!=null){                System.out.println(Thread.currentThread().getName()+"從map緩存中取得連接,Hashcode="+conn.hashCode());            }else{                System.out.println(Thread.currentThread().getName()+"從連接池中得到連接");                conn = dataSource.getConnection();                container.set(conn);            }            if(start){                conn.setAutoCommit(false);//開啟事務,默認事務級別為TRANSACTION_REPEATABLE_READ（4）            }        }catch(Exception e){            System.out.println("連接獲取失敗");            e.printStackTrace();        }        return conn;    }    /***關閉連接*/    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("事物提交異常");                try {                    if(end){                        conn.rollback();                        System.out.println(Thread.currentThread().getName()+"事務已回滾.....hashcode+"+conn.hashCode());                    }                } catch (Exception e1) {                    System.out.println("事物回滾異常");                    e1.printStackTrace();                }                e.printStackTrace();            }finally{                try {                    conn.close();                    System.out.println(Thread.currentThread().getName()+"連接關閉");                    container.remove();//從當前線程移除連接切記                    System.out.println(Thread.currentThread().getName()+"成功移除連接。。。。");                } catch (Exception e2) {                    System.out.println("關閉連接異常，或者是移除緩存中的連接出錯..............");                    e2.printStackTrace();                }            }        }else{            System.out.println("關閉連接時，連接為空");        }    }    public void aa(List<Integer> a,int b){        a.set(0, 2);        b=2;    }    //簡單使用方式    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);    }}