spring连接mysql数据库实现增删改查

连接mysql数据库

数据库引入相关 jar 包新建包，创建一些类新建xml文件，进行配置测试与结果

spring框架将JDBC进行了封装，使用 JdbcTemplate 方便实现对数据库操作
（spring5要求jdk不能低于1.8）

所需jar包

导入方法

dao层
UserDao

package com.dao;

import com.entity.User;

import java.util.List;

public interface UserDao {
    void add(User user);
    void updateUser(User user);
    void delete(String id);
    List findAll();
    User findone();
}

UserDaoImpl

package com.dao;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;
import com.entity.User;

import java.util.List;

@Repository
public class UserDaoImpl implements UserDao {
    //注入 JdbcTemplate
    @Autowired
    private JdbcTemplate jdbcTemplate;

    //添加的方法
    @Override
    public void add(User user) {
        //1 创建 sql 语句
        String sql = "insert into user values(?,?,?)";
        //2 调用方法实现
        Object[] args = {user.getUserId(), user.getUserName(), user.getUserAge()};
        int update = jdbcTemplate.update(sql,args);
        System.out.println(update);

    }

//    修改
    @Override
    public void updateUser(User user) {
        String sql="update user set userName=?,userAge=? where userId=?";
        Object[] args = {user.getUserName(), user.getUserAge(),user.getUserId()};
        int update = jdbcTemplate.update(sql,args);
        System.out.println(update);
    }
//删除
    @Override
    public void delete(String name) {
        String sql = "delete from user where  =?";
        int update = jdbcTemplate.update(sql, name);
        System.out.println(update);
    }

    //查询
    @Override
    public User findone() {
        String sql = "select * from user where userId='1'";
        return   jdbcTemplate.queryForObject(sql , new BeanPropertyRowMapper(User.class));
    }


}

Service层

package com.service;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.dao.UserDao;
import com.entity.User;

import java.util.List;

@Service
public class UserService {
    @Autowired
    private UserDao userDao;

    public void addUser(User user){
        userDao.add(user);
    }
    public void updateuser(User user){
        userDao.updateUser(user);
    }
   	
    public void deleteUser(String id){
        userDao.delete(id);
    }
    public User findoneInfo(){
        return userDao.findone();
    }
}

创建实体类
entity包下创建类
实体类属性必须和数据库中保持一致

package com.entity;

public class User {
    private String userId;
    private String userName;
    private String userAge;

    public void setUserId(String userId) {
        this.userId = userId;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public void setUserAge(String userAge) {
        this.userAge = userAge;
    }

    public String getUserId() {
        return userId;
    }

    public String getUserName() {
        return userName;
    }

    public String getUserAge() {
        return userAge;
    }
    
}

xml文件在src下（这样做为了方便，也可以放在其他地方，调用的时候注意路径问题就行）

代码

在test包下进行测试

package com.test;


import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.entity.User;
import com.service.UserService;
import org.testng.annotations.Test;

import java.util.List;

public class testUserService {
//    增
    @Test
    public void test1(){
        ApplicationContext context =
                new ClassPathXmlApplicationContext("bean1.xml");

        UserService userService = context.getBean("userService", UserService.class);

        User textuser= new User();
        textuser.setUserId("1");
        textuser.setUserName("赛文");
        textuser.setUserAge("16");

        userService.addUser(textuser);
    }
}

增加数据结果

删除数据

//    删
    @Test
    public void test2(){
        ApplicationContext context =
                new ClassPathXmlApplicationContext("bean1.xml");

        UserService userService = context.getBean("userService", UserService.class);

        String name="aotomen";

        userService.deleteUser(name);
    }

删除结果

修改数据

//    改
    @Test
    public void test3() {
        ApplicationContext context =
                new ClassPathXmlApplicationContext("bean1.xml");

        UserService userService = context.getBean("userService", UserService.class);

        User textuser2 = new User();
        textuser2.setUserId("1");
        textuser2.setUserName("泰罗");
        textuser2.setUserAge("16");

        userService.updateuser(textuser2);
    }

修改结果

查询数据

//    查
    @Test
    public void test4(){
        ApplicationContext context =
                new ClassPathXmlApplicationContext("bean1.xml");

        UserService userService = context.getBean("userService", UserService.class);

        User user =userService.findoneInfo();
        System.out.println(user.getUserId()+"n" +user.getUserName()+"n"+user.getUserAge());
    }

查询结果