初始SpringBoot(第一篇):SpringBoot整合Mybatis实现增删改查（CRUD）操作

一 项目架构

开发工具： IntelliJ IDEA 2019.3.3
使用技术： SpringBoot+mybatis+maven+mysql
测试工具： postman
项目搭建：

二 项目实现

1. 数据库设计

create table `user`(
id int(10) primary key auto_increment,
username varchar(30),
password varchar(30),
gender varchar(10)
)
#添加测试数据
insert into user values(default,"zs","123","男");
insert into user values(default,"ls","1234","女");
insert into user values(default,"ww","1235","男");

2. 添加maven依赖(pom.xml)

	<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.8.RELEASE</version>
    </parent>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- springboot 整合mybatis -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.21</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

3. 添加配置文件

这里使用application.yml文件，相对于properties配置文件,yml有着天然树形结构，使得它看起来更加直观,不用重复的去写前缀，

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/test1?useUnicode=true&characterEncoding=utf8
    username: root
    password: abc123
    driver-class-name: com.mysql.jdbc.Driver

useUnicode=true&characterEncoding=utf8的作用：插入数据到mysql时不会出现中文乱码

4. Model层

可以使用Alt+Insert来生成getset方法和构造器方法

package com.example.demo.entity;

/**
 * user实体
 */

public class User {
     
    private int id;
    private String name;
    private String password;
    private String gender;

    public User() {
     
    }

    public User(String name, String password, String gender) {
     
        this.name = name;
        this.password = password;
        this.gender = gender;
    }

    public int getId() {
     
        return id;
    }

    public void setId(int id) {
     
        this.id = id;
    }

    public String getName() {
     
        return name;
    }

    public void setName(String name) {
     
        this.name = name;
    }

    public String getPassword() {
     
        return password;
    }

    public void setPassword(String password) {
     
        this.password = password;
    }

    public String getGender() {
     
        return gender;
    }

    public void setGender(String gender) {
     
        this.gender = gender;
    }

    @Override
    public String toString() {
     
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", password='" + password + '\'' +
                ", gender='" + gender + '\'' +
                '}';
    }
}

5. Dao层

这里通过注解来实现增删改查，可以不用编写对应的xml文件

package com.example.demo.mapper;

import com.example.demo.entity.User;
import org.apache.ibatis.annotations.*;

import java.util.List;

public interface UserMapper {
     
    @Insert("insert into user values(default,#{name},#{password},#{gender})")
    public int insertUser(User user);
    @Select("select * from user")
    public List<User> selectAll();
    @Delete("delete from user where id=#{id}")
    public int deleteUser(int id);
    @Update("update user set name=#{name},password=#{password},gender=#{gender} where id=#{id}")
    public int updateUser(User user);
    @Select("select * from user where name=#{name},password=#{password}")
    public int login(@Param("name") String name,@Param("password") String password);
}

6. service层

package com.example.demo.service;

import com.example.demo.entity.User;
import com.example.demo.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * user服务层
 */

@Service
public class UserService {
     
    @Autowired
    private UserMapper userMapper;

    public int addUser(User user) {
     
        return userMapper.insertUser(user);
    }

    public List<User> findAll() {
     
        return userMapper.selectAll();
    }

    public int updUser(User user) {
     
        return userMapper.updateUser(user);
    }

    public int delUser(int id) {
     
        return userMapper.deleteUser(id);
    }
    public int login(String name,String password){
     
        return userMapper.login(name,password);
    }
}

7. Controller层

做了五个简单的接口，查询全部用户，增加用户，删除用户，修改用户，用户登录

package com.example.demo.controller;

import com.example.demo.entity.User;
import com.example.demo.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class UserController {
     
    @Autowired
    private UserService userService;

    @RequestMapping("index")
    public String index() {
     
        return "Hello world";
    }

    @RequestMapping("/addUser")
    public String addUser() {
     
        User user = new User("zs", "123", "男");
        return userService.addUser(user) > 0 ? "success" : "fail";
    }

    @RequestMapping("/findAll")
    public List<User> findAll() {
     
        return userService.findAll();
    }

    @RequestMapping("/updUser")
    public String updUser(int id) {
     
        User user = new User("ls", "123", "女");
        user.setId(id);
        return userService.updUser(user) > 0 ? "success" : "fail";
    }

    @RequestMapping("/delUser")
    public String delUser(int id) {
     

        return userService.delUser(id) > 0 ? "success" : "fail";
    }

    @RequestMapping("/login")
    public String login(String name, String password) {
     
        return userService.login(name, password) > 0 ? "登录成功" : "登录失败";
    }
}

8. SpringBoot启动类

package com.example.demo;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.example.demo.mapper")
public class DemoApplication {
     

    public static void main(String[] args) {
     
        SpringApplication.run(DemoApplication.class, args);
    }
}

三 项目测试

这里通过postman来测试接口

1.测试项目是否能跑起来

 出现Hellow World表示项目部署成功,报错请检查配置以及注解是否正确

2.查询全部

出现以下结果表示整合mybatis成功，报错请检查application.yml文件名以及文件配置信息是否不对

3.增加用户

4.删除用户

5.修改用户

6.用户登录

四 总结

 曾经看过这么一段话，当你的才华还不足以支撑你的野心时，你就应该静下心来好好学习，在此与各位共勉。