[Java知识库]springboot整合mybatis-starter

POM文件：

  <properties>
    <mybatis.starter.version>1.3.2</mybatis.starter.version>
  </properties>
  <!-- entity基础方法自动生成器 -->
  <dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <scope>provided</scope>
  </dependency>
  <!-- mybatis配置 -->
  <dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>${mybatis.starter.version}</version>
  </dependency>

YAML文件：

spring:
  profiles:
    active: dev
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource  #修改数据源为Druid
    druid:
      master:
        url: jdbc:mysql://localhost:3306/study?autoReconnect=true&useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC&zeroDateTimeBehavior=convertToNull
        username: root
        password: root
      slave:
        enable: true
        url: jdbc:mysql://localhost:3306/study?autoReconnect=true&useUnicode=true&characterEncoding=utf-8&serverTimezone=UTC&zeroDateTimeBehavior=convertToNull
        username: root
        password: root
mybatis: #mybatis配置
  type-aliases-package: cn.xhh.dev.entity
  mapperLocations: classpath:mappers/*.xml

在resources目录中新建mappers目录，在mappers目录中新建UserMapper.xml文件：

<?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">
<mapper namespace="cn.xhh.dev.mapper.UserMapper">

    <sql id="user_all">
        ID, NAME, LEVEL
    </sql>

    <select id="getUser" resultType="cn.xhh.dev.entity.UserEntity">
        SELECT 
        <include refid="user_all"></include>
        FROM USER WHERE ID = #{id,jdbcType=INTEGER}
    </select>

</mapper>

新建mapper包，与controller同级，并在mapper包下新建接口类：

package cn.xhh.dev.mapper;

import cn.xhh.dev.entity.UserEntity;
import org.apache.ibatis.annotations.Mapper;

/**
 * @author Administrator
 */
@Mapper
public interface UserMapper {

    /**
     * 根据ID获取用户信息
     * @param id 主键
     * @return 用户信息
     */
    public UserEntity getUser(int id);
}

新建entity包，与mapper包同级，并在entity包下新建pojo类：

package cn.xhh.dev.entity;

import lombok.Data;

/**
 * 用户表
 * @author Administrator
 */
@Data
public class UserEntity {

    /**
     * 主键ID
     */
    private int id;

    /**
     * 用户名
     */
    private String name;

    /**
     * 用户权限等级
     */
    private int level;
}

编写一个Controller类进行测试：

package cn.xhh.dev.controller;

import cn.xhh.dev.common.annotation.DataSource;
import cn.xhh.dev.common.enums.DataSourcesType;
import cn.xhh.dev.entity.UserEntity;
import cn.xhh.dev.mapper.UserMapper;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

/**
 * @author Administrator
 */
@RestController
@RequestMapping("user")
public class MybatisController {

    private UserMapper userMapper;

    public MybatisController(UserMapper userMapper) {
        this.userMapper = userMapper;
    }

    @RequestMapping("getUser")
    public String getUser(@RequestParam("id") Integer id){
        UserEntity user = userMapper.getUser(id);
        return user.toString();
    }
}

浏览器访问：

http://localhost:8081/user/getUser?id=1