MyBatis+Spring整合

一.配置引入

1. 添加以下依赖到pom.xml

   <!--mysql驱动-->
         <dependency>
             <groupId>mysql</groupId>
             <artifactId>mysql-connector-java</artifactId>
         </dependency>
         <!--mybatis-->
         <dependency>
             <groupId>org.mybatis</groupId>
             <artifactId>mybatis</artifactId>
             <version>3.5.1</version>
         </dependency>
         <!--mybatis spring整合jar包-->
         <dependency>
             <groupId>org.mybatis</groupId>
             <artifactId>mybatis-spring</artifactId>
             <version>2.0.1</version>
         </dependency>
         <!--jdbc-->
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-jdbc</artifactId>
         </dependency>
         <!--单元测试-->
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
         </dependency>

2. 在resources目录下薪增mybatis-config.xml文件,内容如下:

   <?xml version="1.0" encoding="UTF-8" ?>
   <!DOCTYPE configuration
           PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
           "http://mybatis.org/dtd/mybatis-3-config.dtd">
   <configuration>
       <environments default="development">
           <environment id="development">
               <transactionManager type="JDBC"/>
               <dataSource type="POOLED">
                   <property name="driver" value="com.mysql.cj.jdbc.Driver"/>
                   <property name="url" value="jdbc:mysql://10.21.100.77:3306/mybatis?useSSL=true&amp;useUnicode=true&amp;characterEncoding=UTF-8"/>
                   <property name="username" value="root"/>
                   <property name="password" value="${password}"/>
               </dataSource>
           </environment>
       </environments>
       <mappers>
           <mapper resource="com/kaychen/springboot01/dao/UserMapper.xml"/>
       </mappers>
   </configuration>

3. 为了能正常引入mappers文件, 需要在pom.xml文件的<build>模块中增加

   <resources>
             <resource>
                 <directory>src/main/java</directory>
                 <includes>
                     <include>**/*.properties</include>
                     <include>**/*.xml</include>
                 </includes>
                 <filtering>false</filtering>
             </resource>
         </resources>

4. 在com/kaychen/springboot01/目录下创建dao, pojo, controller, service

   

5. 在utils工具类包中创建MybatisUtils.java工具类文件

   package com.kaychen.springboot01.utils;
   
   import org.apache.ibatis.io.Resources;
   import org.apache.ibatis.session.SqlSession;
   import org.apache.ibatis.session.SqlSessionFactory;
   import org.apache.ibatis.session.SqlSessionFactoryBuilder;
   
   import java.io.IOException;
   import java.io.InputStream;
   
   public class MybatisUtils {
       private  static SqlSessionFactory sqlSessionFactory;
       static {
           try {
               String resource = "mybatis-config.xml";
               InputStream inputStream = Resources.getResourceAsStream(resource);
               sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
           } catch (IOException e) {
               e.printStackTrace();
           }
       }
   
       public static SqlSession getSqlSession(){
           return sqlSessionFactory.openSession();
       }
   }

6. 在pojo目录中新增User.java数据库实体类文件

   package com.kaychen.springboot01.pojo;
   
   public class User {
       private int id;
       private String username;
       private String password;
   
       public User(){
       }
       public User(int id,String username, String password){
           this.id = id;
           this.username = username;
           this.password = password;
       }
   
       public int getId(){
           return id;
       }
   
       public String getUsername() {
           return username;
       }
   
       public String getPassword() {
           return password;
       }
   
   }

7. 在dao目录中新增userDao.java接口类文件

   package com.kaychen.springboot01.dao;
   
   import com.kaychen.springboot01.pojo.User;
   
   import java.util.List;
   
   public interface UserDao {
       List<User> listUser();
   }

8. 在dao目录中新增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="com.kaychen.springboot01.dao.UserDao">
       <select id="listUser" resultType="com.kaychen.springboot01.pojo.User">
           select * from mybatis.user
       </select>
   </mapper>

二.junit测试

1.在com/kaychen/springboot01目录下创建dao目录以及UserDaoTest.java文件

package com.kaychen.springboot01.dao;

import com.kaychen.springboot01.pojo.User;
import com.kaychen.springboot01.utils.MybatisUtils;
import org.apache.ibatis.session.SqlSession;
import org.junit.Test;

import java.util.List;


public class UserDaoTest {
    @Test
    public void test(){
        SqlSession sqlSession =  MybatisUtils.getSqlSession();
        UserDao userDao = sqlSession.getMapper(UserDao.class);
        List<User> listUser = userDao.listUser();
        for (User user : listUser) {
            System.out.println(user);
        }
        sqlSession.close();
    }
}

三. 整合springboot

1. 在service中新增UserService.java类文件

   package com.kaychen.springboot01.service;
   
   import com.kaychen.springboot01.dao.UserDao;
   import com.kaychen.springboot01.pojo.User;
   import com.kaychen.springboot01.utils.MybatisUtils;
   import org.apache.ibatis.session.SqlSession;
   
   import java.util.List;
   
   public class UserService {
       public List<User> listUser(){
           SqlSession sqlSession = MybatisUtils.getSqlSession();
        UserDao userdao = sqlSession.getMapper(UserDao.class);
           List<User> data = userdao.listUser();
        return data;
       }
   }

2. 在controller目录中新增UserController.java类文件

   package com.kaychen.springboot01.controller;
   
   import com.kaychen.springboot01.service.UserService;
   import org.springframework.web.bind.annotation.RequestMapping;
   import org.springframework.web.bind.annotation.ResponseBody;
   import org.springframework.web.bind.annotation.RestController;
   
   
   @RestController
   @RequestMapping("/api")
   public class UserController {
       @RequestMapping("/hello")
       @ResponseBody
    public Object listUser(){
           UserService userService = new UserService();
        return userService.listUser();
       }
   }

3. 请求localhost/api/hello得到返回数据

   [
       {
           "id": 1,
           "username": "king",
           "password": "Zhengkai2021"
       }
   ]

参考文档：

1. MyBatis官方文档