SpringBoot+MySQL+MyBatis的入门教程

本博客猫叔的博客，转载请申明出处本系列教程为HMStrange项目附带。历史文章如何在VMware12安装Centos7.6最新版Centos7.6安装Java8Centos7.6安装MySQL+Redis（最新版）教程内容备注：本系列开发工具均为IDEA1、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。DDLCREATE 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xml4、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.Drivermybatis: mapper-locations: classpath*:mapper/Mapper.xml type-aliases-package: com.myself.mybatis.entity5、构建数据库对应的实体类TMsg，这个类放在entitypackage com.myself.mybatis.entity;import lombok.Data;import java.io.Serializable;/* * Created by MySelf on 2019/4/9. /@Datapublic 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. /@Mapperpublic 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. /@Servicepublic 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/UncleCatMy…公众号：Java猫说学习交流群：728698035现架构设计（码农）兼创业技术顾问，不羁平庸，热爱开源，杂谈程序人生与不定期干货。