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最后启动,浏览器输入地址:
SpringBoot 整合 Mybatis
基本信息
技术栈
Spring Boot 2.4.5、Mybatis
学习目的
SpringBoot 整合 Mybatis
项目详解
新建一个 Spring Initializr 项目
创建项目的文件结构以及选择 jdk 的版本
选择项目所需要的依赖
修改项目名,点击 Finish 完成
建好项目后生成的 pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.4.5</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.malf</groupId>
<artifactId>springboot_mybatis</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>springboot_mybatis</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.4</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
修改配置文件
本文不使用 application.properties 文件,而使用更加简洁的 application.yml 文件。将 resource 文件夹下原有的 application.properties 文件删除,创建 application.yml 配置文件(备注:SpringBoot 底层会把 application.yml 文件解析为application.properties),本文创建了两个 yml 文件(application.yml 和 application-dev.yml)
application.yml
spring:
profiles:
active: dev
application-dev.yml
server:
port: 8000
mybatis:
mapper-locations: classpath:mapping/*Mapper.xml
type-aliases-package: com.malf.entity
#showSql
logging:
level:
com:
example:
mapper : debug
spring:
datasource:
url: jdbc:mysql://localhost:3306/springboot_mybatis?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
username: root
password: 123456
driver-class-name: com.mysql.cj.jdbc.Driver
数据库表结构
CREATE TABLE `user` (
`id` int(32) NOT NULL AUTO_INCREMENT,
`userName` varchar(32) NOT NULL,
`passWord` varchar(50) NOT NULL,
`realName` varchar(32) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;
创建实体类实现业务流程
创建包 controller、entity、dao、service,resources 下创建 mapping 文件夹,用于写 sql 语句,也可以用注解的方式直接写在 mapper 文件里。
entity
package com.malf.entity;
/**
* @author 巅峰小词典
* @description
* @date 2021/5/20
* @project springboot_mybatis
*/
public class User {
private Integer id;
private String userName;
private String passWord;
private String realName;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getPassWord() {
return passWord;
}
public void setPassWord(String passWord) {
this.passWord = passWord;
}
public String getRealName() {
return realName;
}
public void setRealName(String realName) {
this.realName = realName;
}
@Override
public String toString() {
return "User{" +
"id=" + id +
", userName='" + userName + '\'' +
", passWord='" + passWord + '\'' +
", realName='" + realName + '\'' +
'}';
}
}
controller
package com.malf.controller;
import com.malf.service.UserService;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import javax.annotation.Resource;
/**
* @author 巅峰小词典
* @description
* @date 2021/5/20
* @project springboot_mybatis
*/
@RestController
@RequestMapping("/user")
public class UserController {
@Resource
private UserService userService;
@RequestMapping("getUser/{id}")
public String GetUser(@PathVariable int id) {
return userService.selectById(id).toString();
}
}
dao
package com.malf.dao;
import com.malf.entity.User;
import org.springframework.stereotype.Repository;
/**
* @author 巅峰小词典
* @description
* @date 2021/5/20
* @project springboot_mybatis
*/
@Repository
public interface UserMapper {
User selectById(int id);
}
service
package com.malf.service;
import com.malf.entity.User;
/**
* @author 巅峰小词典
* @description
* @date 2021/5/20
* @project springboot_mybatis
*/
public interface UserService {
public User selectById(int id);
}
service.impl
package com.malf.service.impl;
import com.malf.entity.User;
import com.malf.dao.UserMapper;
import com.malf.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
/**
* @author 巅峰小词典
* @description
* @date 2021/5/20
* @project springboot_mybatis
*/
@Service
public class UserServiceImpl implements UserService {
@Resource
UserMapper userMapper;
public User selectById(int id){
return userMapper.selectById(id);
}
}
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">
<mapper namespace="com.malf.dao.UserMapper">
<resultMap type="com.malf.entity.User" id="User">
<result column="id" jdbcType="INTEGER" property="id"/>
<result column="userName" jdbcType="VARCHAR" property="userName"/>
<result column="passWord" jdbcType="VARCHAR" property="passWord"/>
<result column="realName" jdbcType="VARCHAR" property="realName"/>
</resultMap>
<select id="selectById" resultType="com.malf.entity.User">
select * from user where id = #{id}
</select>
</mapper>
最终框架结构
在启动类里加上注解用于给出需要扫描的 mapper 文件路径 @MapperScan("com.malf.dao")
package com.malf;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.malf.dao") // 扫描的mapper
public class SpringbootMybatisApplication {
public static void main(String[] args) {
SpringApplication.run(SpringbootMybatisApplication.class, args);
}
}
最后启动,浏览器输入地址:http://localhost:8000/user/getUser/1
测试成功,SpringBoot 整合 Mybatis 基本框架就搭建成功了。
源码参考
springboot_mybatis