springboot成神之——mybatis在spring-boot中使用的几种方式

• 本文介绍mybatis在spring-boot中使用的几种方式
  • 项目结构
  • 依赖
  • WebConfig
  • DemoApplication
  • 方式一——@Select
    • User
    • DemoApplication
  • 方式二——@Select和SqlSession结合
    • User
    • DemoApplication
  • 方式三——xml和SqlSession结合
    • applicationproperties
    • UserTest
    • Userxml
    • TestController

本文介绍mybatis在spring-boot中使用的几种方式

项目结构

依赖

<dependency>
	<groupId>org.mybatis.spring.boot</groupId>
	<artifactId>mybatis-spring-boot-starter</artifactId>
	<version>1.3.2</version>
</dependency>

WebConfig

package com.springlearn.learn.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
@EnableScheduling
public class WebConfig implements WebMvcConfigurer {

    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**").allowedOrigins("*").allowedMethods("GET", "POST", "PUT", "DELETE").allowedOrigins("*")
        .allowedHeaders("*");
    }
}

DemoApplication

package com.springlearn.learn;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {

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

方式一——@Select

User

package com.springlearn.learn.mapper;

import java.util.Map;

import java.util.Map;

import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;

@Mapper
public interface User {
    @Select("select * from test where id=#{id}")
    Map GetUserbyId(@Param("id") Integer id);
}

DemoApplication

@RestController
public class TestController {

    @Autowired
    User user;

    @ResponseBody
    @RequestMapping(value = "/test1", method = RequestMethod.GET)
    public Map Test1(HttpServletRequest request){
        Map result = user.GetUserbyId(1);
        return result;
    }
}

方式二——@Select和SqlSession结合

User

package com.springlearn.learn.mapper;

import java.util.Map;

import java.util.Map;

import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;

@Mapper
public interface User {
    @Select("select * from test where id=#{id}")
    Map GetUserbyId(@Param("id") Integer id);
}

DemoApplication

@RestController
public class TestController {

    @Autowired
    User user;

    @Autowired
    SqlSession sqlSession;

    @ResponseBody
    @RequestMapping(value = "/test2", method = RequestMethod.GET)
    public Map Test2(HttpServletRequest request){
        // 用法一
        Map result = sqlSession.selectOne("com.springlearn.learn.mapper.User.GetUserbyId", 1);

        // 用法二
        User mapper = sqlSession.getMapper(User.class);
        Map result = mapper.GetUserbyId(1);

        return result;
    }
}

方式三——xml和SqlSession结合

applicationproperties

mybatis.mapper-locations=classpath:mapperxml/*.xml

UserTest

package com.springlearn.learn.mapper;

import java.util.Map;

import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;

@Mapper
public interface UserTest {
    Map<String, Object> GetUserbyId(@Param("id") Integer id);
}

Userxml

<?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="com.springlearn.learn.mapper.UserTest">
    <select id="GetUserbyId" parameterType="int" resultType="java.util.Map">
        select * from test where id=#{id}
    </select>
</mapper>

TestController

@RestController
public class TestController {

    @Autowired
    User user;

    @Autowired
    SqlSession sqlSession;

    @ResponseBody
    @RequestMapping(value = "/test3", method = RequestMethod.GET)
    public Map<String, Object> Test3(HttpServletRequest request, @RequestParam("id") int id){
        // 用法一
        Map<String, Object> result = sqlSession.selectOne("com.springlearn.learn.mapper.UserTest.GetUserbyId", id);

        // 用法二
        UserTest mapper = sqlSession.getMapper(UserTest.class);
        System.out.println(mapper.GetUserbyId(id));
        Map<String, Object> result = mapper.GetUserbyId(id);
        
        return result;
    }
}