driver=com.mysql.jdbc.Driver

url=jdbc:mysql://localhost:3306/database01

user=root

password=

package com.dzq.util;

import java.io.FileReader;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.Properties;

public class JDBCUtils {

   private static  Properties prop=null;

   private JDBCUtils(){

   }

   /**

    * 静态代码块，加载数据库配置文件

    */

   static{

       try{

        prop=new Properties();

        prop.load(new FileReader(JDBCUtils.class.getClassLoader().getResource("config.properties").getPath()));

       }catch(Exception e){

           e.printStackTrace();

           throw new RuntimeException();

       }

   }

   /**

    * 获取连接

    */

   public static Connection getConn() throws Exception{

       Class.forName(prop.getProperty("driver"));

       return DriverManager.getConnection(prop.getProperty("url"), prop.getProperty("user"), prop.getProperty("password"));

   }

   /**

    * 关闭连接

    */

   public static void close(ResultSet rs,Statement stat,Connection conn){

       if(rs!=null){

            try {

                rs.close();

            } catch (SQLException e) {

                e.printStackTrace();

            }finally{

                rs=null;

            }

        }

        if(stat!=null){

            try {

                stat.close();

            } catch (SQLException e) {

                e.printStackTrace();

            }finally{

                stat=null;

            }

        }

        if(conn!=null){

            try {

                conn.close();

            } catch (SQLException e) {

                e.printStackTrace();

            }finally{

                conn=null;

            }

        }

   }

}

package com.dzq.jdbc;

import java.sql.Connection;

import java.sql.ResultSet;

import java.sql.Statement;

import org.junit.Test;

import com.dzq.util.JDBCUtils;

public class JDBCDemo2 {

    /**

     * 该类中方法均以JUnit测试的形式给出

     */

    @Test

    public void delete(){

        Connection conn=null;

        Statement stat=null;

        ResultSet rs=null;

        try{

        //2.获取连接

            conn=JDBCUtils.getConn();

        //3.获取传输器对象

            stat=conn.createStatement();

            stat.executeUpdate("delete from user where name='zhaoliu'");

        }catch(Exception e){

            e.printStackTrace();

        }finally{

            JDBCUtils.close(rs, stat, conn);

        }

    }

    @Test

    public void find(){

        Connection conn=null;

        Statement stat=null;

        ResultSet rs=null;

        try{

        //2.获取连接

            conn=JDBCUtils.getConn();

        //3.获取传输器对象

            stat=conn.createStatement();

            rs=stat.executeQuery("select * from user where name='zhaoliu'");

            while(rs.next()){

                String name=rs.getString("name");

                String password=rs.getString("password");

                String email=rs.getString("email");

                System.out.println("name:"+name+"pwd:"+password+"email:"+email);

            }

        }catch(Exception e){

            e.printStackTrace();

        }finally{

            JDBCUtils.close(rs, stat, conn);

        }

    }

    @Test

    public void update(){

        Connection conn=null;

        Statement stat=null;

        try {

        //2.获取连接

            conn=JDBCUtils.getConn();

        //3.获取传输器对象

            stat=conn.createStatement();

            stat.executeUpdate("update user set password=999 where name='zhangsan'");

        } catch (Exception e) {

            e.printStackTrace();

        }finally{

            JDBCUtils.close(null, stat, conn);

        }

    }

    @Test

    public void add(){

        Connection conn=null;

        Statement stat=null;

    //1.注册数据库驱动

        try{

    //2.获取连接

        conn=JDBCUtils.getConn();

    //3.获取传输器对象

        stat=conn.createStatement();

    //4.执行sql语句

        int count=stat.executeUpdate("insert into user values (null,'zhangsan','123456','zhaoliu@qq.com','1999-09-09')");

    //5.处理结果

        if(count>0){

            System.out.println("添加数据成功,影响行数为"+count);

        }else{

            System.out.println("执行失败");

        }

        }catch(Exception e){

            e.printStackTrace();

        }finally{

    //6.关闭资源

            JDBCUtils.close(null, stat, conn);

        }

   }

}