Spring boot 学习笔记 - 整合MyBatis

Posted 2020-08-04 拿铁Latte

Spring boot 学习笔记 （二）- 整合MyBatis

 

Spring Boot中整合MyBatis，并通过注解方式实现映射。

整合MyBatis

以Spring boot 学习笔记 （一）- Hello world 为基础项目，在pom.xml中添加如下依赖

 

<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>

在application.properties 文件下 添加mysql的连接配置（切记不要在行尾留有空格，否则报com.mysql.jdbc.Driver   Class Not Found error,其实只是含有空格导致找不到类）

spring.datasource.url=jdbc:mysql://localhost:3306/test
spring.datasource.username=root
spring.datasource.password=
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

同其他Spring Boot工程一样，简单且简洁的的完成了基本配置，下面看看如何在这个基础下轻松方便的使用MyBatis访问数据库。

添加com.latteyan.entity包，并添加User 类

package com.latteyan.entity;

import java.io.Serializable;

public class User implements Serializable{
    
    private static final long serialVersionUID = 8002149736589557777L;

    private Long id;
    
    private String name;
    
    private Integer age;

    public Long getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

添加com.latteyan.dao包，并添加UserMapper接口

package com.latteyan.dao;

import java.util.List;
import java.util.Map;

import com.latteyan.entity.User;

import org.apache.ibatis.annotations.*;

@Mapper
public interface UserMapper {
    // 通过Parameter新增
    @Insert("INSERT INTO USER(NAME, AGE) VALUES(#{name}, #{age})")
    int insertByParameter(@Param("name") String name, @Param("age") Integer age);
    
    // 通过Map新增
    @Insert("INSERT INTO USER(NAME, AGE) VALUES(#{name,jdbcType=VARCHAR}, #{age,jdbcType=INTEGER})")
    int insertByMap(Map<String, Object> map);  
    
    // 通过Object新增
    @Insert("INSERT INTO USER(NAME, AGE) VALUES(#{name}, #{age})")
    int insertByObject(User user);
    
    // Delete By Id
    @Delete("DELETE FROM user WHERE id =#{id}")
    void delete(Long id);
    
    // Update
    @Update("UPDATE user SET age=#{age} WHERE name=#{name}")
    void update(User user);
    
    // Find by Parameter
    @Select("SELECT * FROM USER WHERE NAME = #{name}")
    User findByName(@Param("name") String name);
    
    // 通过@Results，绑定返回值
    @Results({
        @Result(property = "name", column = "name"),
        @Result(property = "age", column = "age")
    })
    @Select("SELECT name, age FROM user")
    List<User> findAll();  
}

通过UserMapper 接口我们就可以现在访问数据库的功能.

单元测试

package com.latteyan;

import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import com.latteyan.dao.UserMapper;
import com.latteyan.entity.User;

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringbootApplicationTests {

    @Autowired
    private UserMapper userMapper;

    @Test
    public void add() throws Exception {
        // insert by parameter
        userMapper.insertByParameter("zhangShan", 20);
        
        // insert by object
        User user = new User();
        user.setAge(21);
        user.setName("LiSi");
        userMapper.insertByObject(user);
        
        // insert by map
        Map<String, Object> map = new HashMap<>();
        map.put("name", "huangwu");
        map.put("age", 22);
        userMapper.insertByMap(map);
        
        User zhangShan = userMapper.findByName("zhangShan");
        Assert.assertEquals(20, zhangShan.getAge().intValue());
        User LiSi = userMapper.findByName("LiSi");
        Assert.assertEquals(21, LiSi.getAge().intValue());
        User huangwu = userMapper.findByName("huangwu");
        Assert.assertEquals(22, huangwu.getAge().intValue());
    }
    
    @Test
    public void udpate() throws Exception {
        User user = userMapper.findByName("zhangShan");
        user.setAge(50);
        userMapper.update(user);
        
        user = userMapper.findByName("zhangShan");
        Assert.assertEquals(50, user.getAge().intValue());
        
        userMapper.delete(user.getId());
    }
    
    @Test
    public void findAll() throws Exception {
        List<User> users = userMapper.findAll();
        Assert.assertNotNull(users);
    }

}

参考：http://blog.didispace.com/springbootmybatis/