背景

做SpringBoot已经大半年了，之前一直在现成的框架做CRUD和日常业务。没时间自己重头搭建，现在找工作机会来了。

在Maven的POM配置依赖
配置文件添加数据库信息，分别是Mybatis和Spring datasource
CRUD流程 ----> domain、mapper、service、serviceImpl、mapper.xml
REST控制器---->我这里建了一个API包，叫啥不重要

POM.XML依赖

 		<!--MySQL数据库驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <!--阿里巴巴连接池-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.16</version>
        </dependency>
         <!--Mybatis-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.0.1</version>
        </dependency>

yml配置

spring:
#  持久层
  datasource:
    url: jdbc:mysql://120.7X.XX.XX:3306/xxxxxx?useUnicode=true&characterEncoding=utf-8
    username: XXXXX
    password: XXXXX
    driver-class-name: com.mysql.cj.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource

mybatis:
#  实体类
  type-aliases-package: com.teavamc.transsocket.domain
#  mapper文件扫描位置
  mapper-locations: classpath:mapper/*.xml

CRUD流程

实体类 User

package com.teavamc.transsocket.domain;

/**
 * @author 张超 teavamc
 * @Description:TODO
 * @ClassName User
 * @date 2019/4/29 21:36
 **/
public class User {
    private Integer Id;
    private String username;
    private String nickname;
    private String gender;

    public Integer getId() {
        return Id;
    }

    public void setId(Integer id) {
        Id = id;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getNickname() {
        return nickname;
    }

    public void setNickname(String nickname) {
        this.nickname = nickname;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    @Override
    public String toString() {
        return "User{" +
                "Id=" + Id +
                ", username='" + username + '\'' +
                ", nickname='" + nickname + '\'' +
                ", gender='" + gender + '\'' +
                '}';
    }
}

Mapper接口

这里需要注意一下的是两个注解@Mapper与@Repository
@mapper注解是Mybatis提供，面去写XML的烦恼，但是本文还是配套写xml，该注解能够省去在启动器加入@MapperScan
@Repository注解是标注数据访问组件,即DAO组件

package com.teavamc.transsocket.mapper;

import com.teavamc.transsocket.domain.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

import java.util.List;

/**
 * @author 张超 teavamc
 * @Description:TODO
 * @ClassName UserMapper
 * @date 2019/4/29 21:59
 **/
@Mapper
@Repository
public interface UserMapper {

    public List<User> selectUser();

}

service接口

这里的@Service注解标记这是一个业务组件，省去了在applicationContext.xml文件的配置

package com.teavamc.transsocket.service;

import com.teavamc.transsocket.domain.User;

import java.util.List;

/**
 * @author 张超 teavamc
 * @Description:TODO
 * @ClassName IUserService
 * @date 2019/4/29 21:40
 **/
public interface IUserService {

    public List<User> selectUser();
}

Service实现类

package com.teavamc.transsocket.service.impl;

import com.teavamc.transsocket.domain.User;
import com.teavamc.transsocket.mapper.UserMapper;
import com.teavamc.transsocket.service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @author 张超 teavamc
 * @Description:TODO
 * @ClassName UserServiceImpl
 * @date 2019/4/29 21:43
 **/
@Service
public class UserServiceImpl implements IUserService {

    @Autowired
    private UserMapper userMapper;


    @Override
    public List<User> selectUser(){
        return userMapper.selectUser();
    }

}

Mpper.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.teavamc.transsocket.mapper.UserMapper">
    
    <select id="selectUser" resultType="HashMap">
      select Id,username,nickname,gender
      from user
    </select>

</mapper>

REST的GET API接口

package com.teavamc.transsocket.api;

import com.teavamc.transsocket.domain.ApiRes;
import com.teavamc.transsocket.service.IUserService;
import com.teavamc.transsocket.utils.ApiMaker;
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;

/**
 * @author 张超 teavamc
 * @Description:baseApi
 * @ClassName baseApi
 * @date 2019/4/28 22:57
 **/
@RestController
@RequestMapping(value = "/api")
public class baseApi {

    @Autowired
    private IUserService userService;

    /**
        * baseApi
        * @author 张超 teavamc
        * @date 2019/4/28
        * @return java.lang.String
        */
    @GetMapping(value = "/base")
    public ApiRes base(){
        ApiRes res = new ApiRes();
        res.put("data","Request Succeed");
        return res;
    }

    @GetMapping(value = "/selectuser")
    public ApiRes selectUser(){
        return ApiMaker.putList(userService.selectUser());
    }

}

测试

使用PostMan测试API的url

在这里插入图片描述
数据返回成功

后记

API中的ApiRes 对象是我用来封装我自己的JSON数据的，用户规范会返回。
本文的目的就是梳理如何使用Mybatis和Druid实现一个简单的后台CRUD雏形。
适合有基础的同学。

teavamc

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背景