SpringBoot整合Mybatis

准备工作

1. 查看mybatis-spring-boot-starter启动器官方文档

http://mybatis.org/spring-boot-starter/mybatis-spring-boot-autoconfigure/

2. 导入SpringBoot整合Mybatis所需要的依赖

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.3</version>
</dependency>

3. 配置数据库连接信息不变，使用Druid数据源

#配置springboot数据源和数据库驱动
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/mybatis_zr?serverTimezone=PRC&useUnicode=true&characterEncoding=utf-8
    driver-class-name: com.mysql.cj.jdbc.Driver
    password: root
    username: root
    #切换数据源
    type: com.alibaba.druid.pool.DruidDataSource
    #Spring Boot 默认是不注入这些属性值的，需要自己绑定
    #druid 数据源专有配置
    druid:
      initialSize: 5
      minIdle: 5
      maxActive: 20
      maxWait: 60000
      timeBetweenEvictionRunsMillis: 60000
      minEvictableIdleTimeMillis: 300000
      validationQuery: SELECT 1 FROM DUAL
      testWhileIdle: true
      testOnBorrow: false
      testOnReturn: false
      poolPreparedStatements: true

      #配置监控统计拦截的filters，stat:监控统计、log4j：日志记录、wall：防御sql注入
      #如果允许时报错  java.lang.ClassNotFoundException: org.apache.log4j.Priority
      #则导入 log4j 依赖即可，Maven 地址：https://mvnrepository.com/artifact/log4j/log4j
      filters: stat,wall,log4j
      maxPoolPreparedStatementPerConnectionSize: 20
      useGlobalDataSourceStat: true
      connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
server:
  port: 80

4. 测试数据库连接是否成功

5. 创建实体类 ，使用Lombok插件

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    
    private Integer id;
    private String username;
    private String password;
    private Integer gender;
    private Date regist_time;

}

如果没有使用@Mapper注解标准Mapper接口类，则要在使用的类上加上注解@MapperScan注解进行扫描包下的Mapper接口

6. 创建mapper目录以及对应的 Mapper 接口

//@Mapper : 表示本类是一个MyBatis的Mapper
@Mapper
@Repository
public interface UserMapper {

    //查询所有数据信息
    List<User> queryList();
    //根据id查询数据
    User queryById(@Param("id") int id);
    //添加一条数据
    int add(User user);
    //更新一条数据
    int update(User user);
    //根据id删除一条数据
    int delete(@Param("id") int id);


}

7. 对应的Mapper映射文件,UserMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<!--绑定对应的Mapper接口-->
<mapper namespace="com.chenhui.mapper.UserMapper">
<!--查询所有的数据-->
    <select id="queryList" resultType="user">
        select * from t_user
    </select>
<!--根据id查询一条数据-->
    <select id="queryById" resultType="user">
        select * from t_user where id = #{id}
    </select>
<!--插入一条数据-->
    <insert id="add" parameterType="user">
        insert into t_user (username,password,gender,regist_time)
        values(#{username},#{password},#{gender},#{regist_time})
    </insert>
<!--    更新一条数据-->
    <update id="update" parameterType="user">
        update t_user set username=#{username},password=#{password},gender=#{gender},
        regist_time=#{regist_time} where id=#{id}
    </update>
<!--    删除一条数据-->
    <delete id="delete" parameterType="_int">
        delete from t_user where id =#{id}
    </delete>
</mapper>

8. 配置一些Mybatis的配置信息

#配置Mybatis一些配置，例如mapper.xml文件路径位置，以及实体类的别名
mybatis:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.chenhui.pojo

9. 编写controller类进行测试

@RestController
public class TestController {

    //注入UserMapper对象进行增删改查操作
    @Autowired
    UserMapper userMapper;

    @RequestMapping("/query")
    public List<User> query()  {
        //测试查询所有数据
        List<User> users = userMapper.queryList();
        return users;
    }

    @RequestMapping("/queryById")
    public User queryById()  {
        //根据id查询一条数据
        User user = userMapper.queryById(8);
        return user;
    }

    @RequestMapping("/add")
    public int add() {
        //添加一条数据
        int result = userMapper.add(new User(null, "hhh", "789", 1, new Date()));
        return result;
    }
    @RequestMapping("/update")
    public int update()  {
        //添加一条数据
        int result = userMapper.update(new User(15,"ch","8888",0,new Date()));
        return result;
    }

    @RequestMapping("/delete")
    public int delete()  {
        //添加一条数据
        int result = userMapper.delete(15);
        return result;
    }
}

10. 启动项目测试成功即可！