SpringBoot+MySQL+MyBatis搭建

2021-03-08

Spring Boot 框架是 Java 平台上的一种开源轻量级应用框架，提供具有控制反转特性的容器。

步骤

初始化项目
配置 Maven 国内镜像
配置 Gradle 国内镜像
配置项目
生成 Entity
基础测试

初始化项目

通过 spring initializr 网站或集成开发工具IDEA、STS等初始化项目。
spring initializr 地址：https://start.spring.io/

初始化项目时勾选上 Spring Web + MySQL Driver + MyBatis Framework
JPA用于对象关系映射ORM
其他初始化信息详见下图：

配置 Maven 国内镜像

默认仓库位置：C:\Users\用户\.m2\repository

IDEA查看Maven配置信息
勾选两个Override

C:\Users\用户\.m2 下新建settings.xml，内容如下：

<?xml version="1.0" encoding="UTF-8"?>

<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0" 
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
          xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 
          http://maven.apache.org/xsd/settings-1.0.0.xsd">
          
  <!--本地仓库目录，注意此处目录应该与上面的设置Local Repository一致-->
  <localRepository>C:/Users/MagicBooK/.m2/repository</localRepository>
	<mirrors>
	  <mirror>
	    <!--该镜像的id-->
	    <id>nexus-aliyun</id>
	    <!--该镜像用来取代的远程仓库，central是中央仓库的id-->
	    <mirrorOf>central</mirrorOf>
	    <name>Nexus aliyun</name>
	    <!--该镜像的仓库地址，这里是用的阿里的仓库-->
	    <url>http://maven.aliyun.com/nexus/content/groups/public</url>
	  </mirror>
	</mirrors>
</settings>

配置 Gradle 国内镜像

详细参考文章：https://www.cnblogs.com/huiyi0521/p/10997152.html

配置项目

数据库MySQL配置 + MyBatis配置
application.properties

# 数据库配置
spring.datasource.url=jdbc:mysql://xxx:3306/xxx?useUnicode=true&characterEncoding=UTF-8&useSSL=false&autoReconnect=true&failOverReadOnly=false&serverTimezone=GMT%2B8
spring.datasource.username=xxx
spring.datasource.password=xxx
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

# MyBatis 配置
# 搜索指定包别名
mybatis.type-aliases-package=com.clh.literature.model
# 配置mapper的扫描，找到所有的mapper.xml映射文件
mybatis.mapper-locations=classpath*:mapper/**/*.xml

项目结构

生成 Entity

详细参考文章：https://blog.csdn.net/tianyaleixiaowu/article/details/78204453

基础测试

启动类 LiteratureApplication 不作更改

package com.clh.literature;

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

@SpringBootApplication
public class LiteratureApplication {

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

}

Controller层：UserController.java

package com.clh.literature.controller;

import com.clh.literature.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

//@Controller + @ResponseBody
@RestController
public class UserController {

    @Autowired
    private UserService userService;

    // 获取某用户数据
    @GetMapping(value = "/user/{openId}")
    public String getOneUser(@PathVariable String openId){
        return userService.getOneUser(openId);
    }
}

Service层：UserService.java

package com.clh.literature.service;

import com.clh.literature.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class UserService{

    @Autowired
    private JsonApi jsonApi;

    @Autowired
    private UserMapper userMapper;

    public String getOneUser(String openId){
      try {
          Object userObject = JSON.toJSON(userMapper.getOneUser(openId));
          return jsonApi.toJson(1, userObject);
      }catch (Exception e){
          return jsonApi.toJson(0, null);
      }
    }
}

Mapper层：UserMapper.java

package com.clh.literature.mapper;

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

@Mapper
public interface UserMapper {

    @Select("SELECT * FROM user WHERE open_id = #{openId};")
    // table列属性与Model变量不匹配，需要指定映射关系。
    // @Result(column = "xxx", property = "xxxx")
    @Result(column = "open_id", property = "openId")
    @Result(column = "pen_name", property = "penName")
    @Result(column = "head_portrait", property = "headPortrait")
    @Result(column = "freeze_whether", property = "freezeWhether")
    User getOneUser(String openId);
}

Model层：User.java

package com.clh.literature.model;


public class User {

  private String openId;
  private String penName;
  private String headPortrait;
  private String signature;
  private int integral;
  private String title;
  private Boolean freezeWhether;


  public String getOpenId() {
    return openId;
  }

  public void setOpenId(String openId) {
    this.openId = openId;
  }


  public String getPenName() {
    return penName;
  }

  public void setPenName(String penName) {
    this.penName = penName;
  }


  public String getHeadPortrait() {
    return headPortrait;
  }

  public void setHeadPortrait(String headPortrait) {
    this.headPortrait = headPortrait;
  }


  public String getSignature() {
    return signature;
  }

  public void setSignature(String signature) {
    this.signature = signature;
  }


  public int getIntegral() {
    return integral;
  }

  public void setIntegral(int integral) {
    this.integral = integral;
  }


  public String getTitle() {
    return title;
  }

  public void setTitle(String title) {
    this.title = title;
  }


  public Boolean getFreezeWhether() {
    return freezeWhether;
  }

  public void setFreezeWhether(Boolean freezeWhether) {
    this.freezeWhether = freezeWhether;
  }

}

common层：JsonApi.java

package com.clh.literature.common;

import com.alibaba.fastjson.JSONObject;
import org.springframework.stereotype.Service;

@Service
public class JsonApi {
    public String toJson(int code, Object data){
        JSONObject jsonObject = new JSONObject();

        jsonObject.put("code", code);
        jsonObject.put("data", data);

        return jsonObject.toJSONString();
    }
}

浏览器，输入URL：http://localhost:8080/user?openId=yegetaier 测试