1、创建mysql测试表 

 

2、按下图创建3个文件夹与3个类

 

3、三个类的代码

PersionDao ：目录(Data Access Object), 数据访问对象是第一个面向对象的数据库接口 

1 package com.test.dao; 2  3 import com.test.entity.Person; 4  5 import java.sql.DriverManager; 6 import java.sql.PreparedStatement; 7 import java.sql.ResultSet; 8 import java.sql.SQLException; 9 10 /**11  * Created by wdw on 2017/9/7.12  */13 public class PersonDao {14 15     private final static String DRIVER = "com.mysql.jdbc.Driver";16     private final static String URL = "jdbc:mysql://localhost:3306/wdw";17     private final static String USERNAME = "root";18     private final static String PASSWORD = "123456";19 20     /**21      * 添加一个人22      *23      * @param person24      * @return boolean25      */26     public boolean insert(Person person) {27         boolean flag = false;//28         try {29             Class.forName(DRIVER);//加载数据库驱动30             java.sql.Connection conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);31 //            使用jar包中的connection接口，并通过DriveManager类的静态方法getConnection()创建连接对象conn32             String sql = "INSERT INTO sys_users(id,name,code) VALUES(?,?,?)";//编写sql语句33             PreparedStatement ps = conn.prepareStatement(sql);创建预处理对象ps34             ps.setInt(1, person.getId());35             ps.setString(2, person.getName());36             ps.setString(3, person.getCode());37 38             if (ps.executeUpdate() > 0) {39                 flag = true;40             }41             System.out.print(flag);42             ps.close();43             conn.close();44 45         } catch (ClassNotFoundException e) {46 47             e.printStackTrace();48         } catch (SQLException e) {49             e.printStackTrace();50         }51         return flag;52     }53 54     /**55      * 添加一个人56      *57      * @param id58      * @return boolean59      */60     public Person selectById(String id) {61         Person p = new Person();62         try {63             Class.forName(DRIVER);//加载数据库驱动64             java.sql.Connection conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);65             String sql = "delete sys_users where id=" + id;//编写sql语句66             PreparedStatement ps = conn.prepareStatement(sql);创建预处理对象ps67             ResultSet r = ps.executeQuery();68             while (r.next()) {69                 p.setId(r.getInt("id"));70                 p.setName((r.getString("code")));71                 p.setCode(r.getString("name"));72             }73 74             ps.close();75             conn.close();76 77         } catch (ClassNotFoundException e) {78 79             e.printStackTrace();80         } catch (SQLException e) {81             e.printStackTrace();82         }83         return p;84     }85 86 }

entity：entity目录(实体)，实体就是一个特定的软件模块。

1 package com.test.entity; 2  3 /** 4  * Created by wdw on 2017/9/7. 5  */ 6 public class Person { 7  8     private int id; 9     private String code;10     private String name;11 12     public int getId() {13         return id;14     }15 16     public void setId(int id) {17         this.id = id;18     }19 20     public String getCode(){21         return  this.code;22 23     }24     public  void  setCode(String code)25     {26         this.code=code;27 28     }29     public String getName(){30         return  this.name;31 32     }33     public  void  setName(String name)34     {35         this.name=name;36 37     }38 }

test：test目录，最终的试行测试。

1 package com.test.test; 2  3 import com.test.dao.PersonDao; 4 import com.test.entity.Person; 5  6 /** 7  * Created by wdw on 2017/9/7. 8  */ 9 public class test {10     public static void main(String[] args) {11         Person ps = new Person();12         ps.setId(1);13         ps.setCode("编号");14         ps.setName("张三");15         PersonDao s = new PersonDao();16         boolean aResult = s.insert(ps);  //add a use17         boolean uResult = s.insert(ps);  //delete a use18         boolean dResult = s.insert(ps);  //delete a use19     }20 21 }

 

4、运行测试，记得在main断点。