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本系列教程为HMStrange项目附带。
历史文章
教程内容
备注：本系列开发工具均为IDEA
1、构建项目，选择Lombok、Web、MySQL、MyBatis四个基本的Maven依赖。
大家可以看看pom文件
<?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 http://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>2.1.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.myself.mybatis</groupId>
<artifactId>datademo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>datademo</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-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.0.1</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
2、准备MySQL，这里可以参考历史文章的安装MySQL环节，我新建了一个数据库，针对这个项目，构建了一张简单的表。
DDL
CREATE TABLE `t_msg` (
`id` int(11) NOT NULL,
`message` varchar(255) DEFAULT NULL COMMENT '信息',
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
3、构建项目目录，我构建了一个经典的web项目目录结构，entity实体类、mapper映射、service接口、impl接口实现、controller业务访问、resources/mapper包用于存放xml
4、填写application.yml，默认生成不是yml，不过我觉得yml视觉效果好一些，就改了一下，我们需要填写数据库信息，还有mybatis的数据库映射地址，实体类地址
spring:
datasource:
url: jdbc:mysql://192.168.192.133:3306/datademo?characterEncoding=utf-8&useSSL=false
username: root
password: password
driver-class-name: com.mysql.cj.jdbc.Driver
mybatis:
mapper-locations: classpath*:mapper/*Mapper.xml
type-aliases-package: com.myself.mybatis.entity
5、构建数据库对应的实体类TMsg，这个类放在entity
package com.myself.mybatis.entity;
import lombok.Data;
import java.io.Serializable;
/**
* Created by MySelf on 2019/4/9.
*/
@Data
public class TMsg implements Serializable {
private Integer id;
private String message;
}
6、构建对应的Mapper接口（其实就类似dao层），这里与TMsgMapper.xml文件对应关系
package com.myself.mybatis.mapper;
import com.myself.mybatis.entity.TMsg;
import org.apache.ibatis.annotations.Mapper;
/**
* Created by MySelf on 2019/4/9.
*/
@Mapper
public interface TMsgMapper {
public TMsg findById(Integer id);
}
<?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.myself.mybatis.mapper.TMsgMapper">
<select id="findById" resultType="com.myself.mybatis.entity.TMsg">
SELECT id,message from t_msg WHERE id = #{id}
</select>
</mapper>
我这边就单纯一个方法，大家可以扩展自己的方法。
7、service层与其实现，这个比较简单，一般做过web项目的都了解
package com.myself.mybatis.service;
import com.myself.mybatis.entity.TMsg;
/**
* Created by MySelf on 2019/4/9.
*/
public interface TMsgService {
public TMsg findById(Integer id);
}
package com.myself.mybatis.service.impl;
import com.myself.mybatis.entity.TMsg;
import com.myself.mybatis.mapper.TMsgMapper;
import com.myself.mybatis.service.TMsgService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
/**
* Created by MySelf on 2019/4/9.
*/
@Service
public class TMsgServiceImpl implements TMsgService {
@Autowired
private TMsgMapper tMsgMapper;
@Override
public TMsg findById(Integer id) {
return tMsgMapper.findById(id);
}
}
8、controller层，我这边构建了一个get方法，通过id获取信息。
package com.myself.mybatis.controller;
import com.myself.mybatis.entity.TMsg;
import com.myself.mybatis.service.TMsgService;
import org.apache.ibatis.annotations.Param;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
/**
* Created by MySelf on 2019/4/9.
*/
@RestController
@RequestMapping("/msg")
public class TMsgController {
@Autowired
private TMsgService tMsgService;
@GetMapping("/getMsg")
public String getMsg(@Param("id") Integer id){
TMsg tMsg = tMsgService.findById(id);
return tMsg.getMessage();
}
}
9、启动项目，并使用Postman测试
10、项目下载地址
欢迎到HMStrange项目进行下载：https://github.com/UncleCatMySelf/HMStrange/tree/master/doc/demo/datademo
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