SpringBoot整合MyBatis

╰+哭是因爲堅強的太久メ 2022-05-25 13:49 306阅读 0赞

一、数据准备

  1. CREATE TABLE `tb_user` ( `id` int(11) NOT NULL AUTO_INCREMENT COMMENT 'ID', `username` varchar(50) NOT NULL COMMENT '用户名', `age` int(11) NOT NULL COMMENT '年龄', `ctm` datetime NOT NULL COMMENT '创建时间', PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8
  3. INSERT INTO `db_test`.`tb_user` (`username`, `age`, `ctm`) VALUES('张三', '18', NOW()) ;
  4. INSERT INTO `db_test`.`tb_user` (`username`, `age`, `ctm`) VALUES('李四', '20', NOW()) ;
  5. INSERT INTO `db_test`.`tb_user` (`username`, `age`, `ctm`) VALUES('王五', '19', NOW()) ;

二、引入依赖

  1. <!-- Spring-Mybatis -->
  2.         <dependency>
  3.             <groupId>org.mybatis.spring.boot</groupId>
  4.             <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.0</version>             </dependency>
  6.         <!-- MySQL -->
  7.         <dependency>
  8.             <groupId>mysql</groupId>
  9.             <artifactId>mysql-connector-java</artifactId>
  10.         </dependency>

另外web依赖也需要，因为我们采用MVC模式。

  1. <!-- Add typical dependencies for a web application -->
  2.         <dependency>
  3.             <groupId>org.springframework.boot</groupId>
  4.             <artifactId>spring-boot-starter-web</artifactId>
  5.         </dependency>

三、数据库配置文件

  1. spring:
  2.   datasource:
  3.     driver-class-name: com.mysql.jdbc.Driver
  4.     url: jdbc:mysql://localhost:3306/db_user
  5.     username: root
  6.     password: root

四、代码

最开始使用mybati比较麻烦，各种配置文件、实体类、dao层映射关联、还有一大推其它配置。当然mybatis也发现了这种弊端，初期开发了generator可以根据表结果自动生产实体类、配置文件和dao层代码，可以减轻一部分开发量；后期也进行了大量的优化可以使用注解了。

于是两种使用方式都介绍一下，一、无配置注解版 二、配置文件版

1.无配置文件注解版

加入配置文件

  1. mybatis:
  2.   type-aliases-package: cn.saytime.bean

这里写图片描述

实体类User.class

  1. package cn.saytime.bean;
  3. import java.util.Date;
  5. /** * @ClassName cn.saytime.bean.User * @Description * @date 2017-07-04 22:47:28 */
  6. public class User {
  8.     private int id;
  9.     private String username;
  10.     private int age;
  11.     private Date ctm;
  13.     public User() {
  14.     }
  16.     public User(String username, int age) {
  17.         this.username = username;
  18.         this.age = age;
  19.         this.ctm = new Date();
  20.     }
  22.     // Getter、Setter
  23. }

UserMapper.class

  1. package cn.saytime.mapper;
  3. import cn.saytime.bean.User;
  4. import org.apache.ibatis.annotations.Delete;
  5. import org.apache.ibatis.annotations.Insert;
  6. import org.apache.ibatis.annotations.Param;
  7. import org.apache.ibatis.annotations.Select;
  8. import org.apache.ibatis.annotations.Update;
  10. import java.util.List;
  12. // @Mapper 这里可以使用@Mapper注解，但是每个mapper都加注解比较麻烦，所以统一配置@MapperScan在扫描路径在application类中
  13. public interface UserMapper {
  15.     @Select("SELECT * FROM tb_user WHERE id = #{id}")
  16.     User getUserById(Integer id);
  18.     @Select("SELECT * FROM tb_user")
  19.     public List<User> getUserList();
  21.     @Insert("insert into tb_user(username, age, ctm) values(#{username}, #{age}, now())")
  22.     public int add(User user);
  24.     @Update("UPDATE tb_user SET username = #{user.username} , age = #{user.age} WHERE id = #{id}")
  25.     public int update(@Param("id") Integer id, @Param("user") User user);
  27.     @Delete("DELETE from tb_user where id = #{id} ")
  28.     public int delete(Integer id);
  29. }

Mybatis 注解使用 http://www.mybatis.org/mybatis-3/zh/java-api.html

UserService.class

  1. package cn.saytime.service;
  3. import cn.saytime.bean.User;
  4. import org.springframework.stereotype.Service;
  6. import java.util.List;
  8. /** * @ClassName cn.saytime.service.UserService * @Description */
  9. public interface UserService {
  11.     User getUserById(Integer id);
  13.     public List<User> getUserList();
  15.     public int add(User user);
  17.     public int update(Integer id, User user);
  19.     public int delete(Integer id);
  20. }

UserServiceimpl.class

  1. package cn.saytime.service.impl;
  3. import cn.saytime.bean.User;
  4. import cn.saytime.mapper.UserMapper;
  5. import cn.saytime.service.UserService;
  6. import org.springframework.beans.factory.annotation.Autowired;
  7. import org.springframework.stereotype.Service;
  9. import java.util.List;
  11. /** * @ClassName cn.saytime.service.impl.UserServiceImpl * @Description */
  12. @Service public class UserServiceImpl implements UserService {
  14.     @Autowired private UserMapper userMapper;
  16.     @Override public User getUserById(Integer id) {
  17.         return userMapper.getUserById(id);
  18.     }
  20.     @Override public List<User> getUserList() {
  21.         return userMapper.getUserList();
  22.     }
  24.     @Override public int add(User user) {
  25.         return userMapper.add(user);
  26.     }
  28.     @Override public int update(Integer id, User user) {
  29.         return userMapper.update(id, user);
  30.     }
  32.     @Override public int delete(Integer id) {
  33.         return userMapper.delete(id);
  34.     }
  35. }

JsonResult.class 通用json返回类

  1. package cn.saytime.bean;
  3. public class JsonResult {
  5.     private String status = null;
  7.     private Object result = null;
  9.     public JsonResult status(String status) {
  10.         this.status = status;
  11.         return this;
  12.     }
  14.     // Getter Setter
  15. }

UserController.class（Restful风格）

  1. package cn.saytime.web;
  3. import cn.saytime.bean.JsonResult;
  4. import cn.saytime.bean.User;
  5. import cn.saytime.service.UserService;
  6. import org.springframework.beans.factory.annotation.Autowired;
  7. import org.springframework.http.HttpStatus;
  8. import org.springframework.http.ResponseEntity;
  9. import org.springframework.web.bind.annotation.PathVariable;
  10. import org.springframework.web.bind.annotation.RequestBody;
  11. import org.springframework.web.bind.annotation.RequestMapping;
  12. import org.springframework.web.bind.annotation.RequestMethod;
  13. import org.springframework.web.bind.annotation.RequestParam;
  14. import org.springframework.web.bind.annotation.RestController;
  16. import java.util.List;
  18. /** * @ClassName cn.saytime.web.UserController * @Description * @date 2017-07-04 22:46:14 */
  19. @RestController
  20. public class UserController {
  22.     @Autowired
  23.     private UserService userService;
  25.     /** * 根据ID查询用户 * @param id * @return */
  26.     @RequestMapping(value = "user/{id}", method = RequestMethod.GET)
  27.     public ResponseEntity<JsonResult> getUserById (@PathVariable(value = "id") Integer id){
  28.         JsonResult r = new JsonResult();
  29.         try {
  30.             User user = userService.getUserById(id);
  31.             r.setResult(user);
  32.             r.setStatus("ok");
  33.         } catch (Exception e) {
  34.             r.setResult(e.getClass().getName() + ":" + e.getMessage());
  35.             r.setStatus("error");
  36.             e.printStackTrace();
  37.         }
  38.         return ResponseEntity.ok(r);
  39.     }
  41.     /** * 查询用户列表 * @return */
  42.     @RequestMapping(value = "users", method = RequestMethod.GET)
  43.     public ResponseEntity<JsonResult> getUserList (){
  44.         JsonResult r = new JsonResult();
  45.         try {
  46.             List<User> users = userService.getUserList();
  47.             r.setResult(users);
  48.             r.setStatus("ok");
  49.         } catch (Exception e) {
  50.             r.setResult(e.getClass().getName() + ":" + e.getMessage());
  51.             r.setStatus("error");
  52.             e.printStackTrace();
  53.         }
  54.         return ResponseEntity.ok(r);
  55.     }
  57.     /** * 添加用户 * @param user * @return */
  58.     @RequestMapping(value = "user", method = RequestMethod.POST)
  59.     public ResponseEntity<JsonResult> add (@RequestBody User user){
  60.         JsonResult r = new JsonResult();
  61.         try {
  62.             int orderId = userService.add(user);
  63.             if (orderId < 0) {
  64.                 r.setResult(orderId);
  65.                 r.setStatus("fail");
  66.             } else {
  67.                 r.setResult(orderId);
  68.                 r.setStatus("ok");
  69.             }
  70.         } catch (Exception e) {
  71.             r.setResult(e.getClass().getName() + ":" + e.getMessage());
  72.             r.setStatus("error");
  74.             e.printStackTrace();
  75.         }
  76.         return ResponseEntity.ok(r);
  77.     }
  79.     /** * 根据id删除用户 * @param id * @return */
  80.     @RequestMapping(value = "user/{id}", method = RequestMethod.DELETE)
  81.     public ResponseEntity<JsonResult> delete (@PathVariable(value = "id") Integer id){
  82.         JsonResult r = new JsonResult();
  83.         try {
  84.             int ret = userService.delete(id);
  85.             if (ret < 0) {
  86.                 r.setResult(ret);
  87.                 r.setStatus("fail");
  88.             } else {
  89.                 r.setResult(ret);
  90.                 r.setStatus("ok");
  91.             }
  92.         } catch (Exception e) {
  93.             r.setResult(e.getClass().getName() + ":" + e.getMessage());
  94.             r.setStatus("error");
  96.             e.printStackTrace();
  97.         }
  98.         return ResponseEntity.ok(r);
  99.     }
  101.     /** * 根据id修改用户信息 * @param user * @return */
  102.     @RequestMapping(value = "user/{id}", method = RequestMethod.PUT)
  103.     public ResponseEntity<JsonResult> update (@PathVariable("id") Integer id, @RequestBody User user){
  104.         JsonResult r = new JsonResult();
  105.         try {
  106.             int ret = userService.update(id, user);
  107.             if (ret < 0) {
  108.                 r.setResult(ret);
  109.                 r.setStatus("fail");
  110.             } else {
  111.                 r.setResult(ret);
  112.                 r.setStatus("ok");
  113.             }
  114.         } catch (Exception e) {
  115.             r.setResult(e.getClass().getName() + ":" + e.getMessage());
  116.             r.setStatus("error");
  118.             e.printStackTrace();
  119.         }
  120.         return ResponseEntity.ok(r);
  121.     }
  123. }

Application.java

  1. package cn.saytime;
  3. import org.mybatis.spring.annotation.MapperScan;
  4. import org.springframework.boot.SpringApplication;
  5. import org.springframework.boot.autoconfigure.SpringBootApplication;
  7. @SpringBootApplication
  8. @MapperScan("cn.saytime.mapper")
  9. public class SpringbootMybaitsApplication { 
  11.     public static void main(String[] args) {
  12.         SpringApplication.run(SpringbootMybaitsApplication.class, args);
  13.     }
  14. }

使用PostMan通过测试。

2.配置文件版

加入配置文件

  1. mybatis:
  2.   mapper-locations: classpath:mybatis/mapper/*.xml
  3.   config-location: classpath:mybatis/mybatis-config.xml

项目目录结构：

这里写图片描述

代码部分，相比于上面那种方式，改变的只有配置文件以及下面几个部分。

UserMapper.class

  1. package cn.saytime.mapper;
  3. import cn.saytime.bean.User;
  4. import org.apache.ibatis.annotations.Delete;
  5. import org.apache.ibatis.annotations.Insert;
  6. import org.apache.ibatis.annotations.Param;
  7. import org.apache.ibatis.annotations.Select;
  8. import org.apache.ibatis.annotations.Update;
  9. import org.springframework.stereotype.Repository;
  11. import java.util.List;
  13. /** * @ClassName cn.saytime.mapper.UesrMapper * @Description */
  14. @Repository public interface UserMapper {
  16.     User getUserById(Integer id);
  18.     public List<User> getUserList();
  20.     public int add(User user);
  22.     public int update(@Param("id") Integer id, @Param("user") User user);
  24.     public int delete(Integer id);
  25. }

mybatis-config.xml

  1. <?xml version="1.0" encoding="UTF-8" ?>
  2. <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
  3. <configuration>
  4.     <typeAliases>
  5.     </typeAliases>
  6. </configuration>

userMapper.xml

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
  3. <mapper namespace="cn.saytime.mapper.UserMapper" >
  4.     <resultMap id="BaseResultMap" type="cn.saytime.bean.User" >
  5.         <id column="id" property="id" jdbcType="INTEGER" />
  6.         <result column="username" property="username" jdbcType="VARCHAR" />
  7.         <result column="age" property="age" jdbcType="INTEGER" />
  8.         <result column="ctm" property="ctm" jdbcType="TIMESTAMP"/>
  9.     </resultMap>
  11.     <sql id="Base_Column_List" >
  12.         id, username, age, ctm
  13.     </sql>
  15.     <select id="getUserList" resultMap="BaseResultMap" >
  16.         SELECT
  17.         <include refid="Base_Column_List" />
  18.         FROM tb_user
  19.     </select>
  21.     <select id="getUserById" parameterType="java.lang.Integer" resultMap="BaseResultMap" >
  22.         SELECT
  23.         <include refid="Base_Column_List" />
  24.         FROM tb_user
  25.         WHERE id = #{id}
  26.     </select>
  28.     <insert id="add" parameterType="cn.saytime.bean.User" >
  29.         INSERT INTO
  30.         tb_user
  31.         (username,age,ctm)
  32.         VALUES
  33.         (#{username}, #{age}, now())
  34.     </insert>
  36.     <update id="update" parameterType="java.util.Map" >
  37.         UPDATE
  38.         tb_user
  39.         SET
  40.         username = #{user.username},age = #{user.age}
  41.         WHERE
  42.         id = #{id}
  43.     </update>
  45.     <delete id="delete" parameterType="java.lang.Integer" >
  46.         DELETE FROM
  47.         tb_user
  48.         WHERE
  49.         id = #{id}
  50.     </delete>
  51. </mapper>

上面这种方式也使用PostMan通过测试。

五、简要说明

不知道大家有没有注意到一点，就是引入Springboot-mybatis依赖的时候，并不是spring官方的starter，往常的springboot集成的依赖，比如web，redis等，groupId以及artifactId的地址如下：

  1. <dependency>
  2.             <groupId>org.springframework.boot</groupId>
  3.             <artifactId>spring-boot-starter-web</artifactId>
  4.         </dependency>

而这里是mybatis为spring提供的starter依赖，所以依赖地址是：

  1. <dependency>
  2.             <groupId>org.mybatis.spring.boot</groupId>
  3.             <artifactId>mybatis-spring-boot-starter</artifactId>
  4.             <version>1.3.0</version>
  5.         </dependency>

而且值得注意的是，这里必须要指定版本号，往常我们使用springboot之所以不需要指定版本号，是因为我们引入的Maven Parent 中指定了SpringBoot的依赖，SpringBoot官方依赖Pom文件中已经指定了它自己集成的第三方依赖的版本号，对于Mybatis，Spring官方并没有提供自己的starter，所以必须跟正常的maven依赖一样，要加版本号。

SpringBoot自己集成的starter依赖，可以查看 http://docs.spring.io/spring-boot/docs/1.5.4.RELEASE/reference/htmlsingle/#using-boot-starter

参考：https://blog.csdn.net/saytime/article/details/74783296

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