Springboot项目搭建SSM（Springboot+MySql+Mybatis-plus）

实现功能

搭建SSM，采用SpringBoot+MYSQL+Mybatis-plus

演示的接口demo实现功能，查询数据库中的SYS_Message表数据的内容

实现步骤

一、项目创建

1.File→New→Project

 2.选择Spring Initializr,点击next

3.选择Java版本，建立自己需要的项目名称，点击next

 4.Dependencies,Web勾选“Spring Web”

 SQL 勾选 “JDBC API”、“Mybatis Framework”和“MySQL Driver”

5.点击Finish，由于我建立的demo有重名了，所以建立了demo66

 6.删除不用的文件，.mvn下的wrapper文件夹，根目录的HELP.md、mvnw、mvnw.cmd和application.properties.

删除后目录结构

7.在pom.xml文件中增加Maven依赖

    4.0.0
    
        org.springframework.boot
        spring-boot-starter-parent
        2.5.5
         
    
    com.example
    demo
    0.0.1-SNAPSHOT
    demo
    Demo project for Spring Boot
    
        1.8
    
    
        
            org.springframework.boot
            spring-boot-starter-jdbc
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.mybatis.spring.boot
            mybatis-spring-boot-starter
            2.2.0
        

        
            mysql
            mysql-connector-java
            runtime
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        
        
        
            com.baomidou
            mybatis-plus-boot-starter
            3.4.1
        

        
        
            mysql
            mysql-connector-java
            runtime
        
        
            com.alibaba
            druid-spring-boot-starter
            1.2.8
        
        
            org.projectlombok
            lombok
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    
    
        
            prod
            
                prod
            
        
        
            dev
            
                dev
            
        
        
            test
            
                test
            
        
    

 8.添加yml文件，在src的resources文件夹，右键→New→File，新建application.yml文件

application.yml的内容为

# 指定执行环境
spring:
  profiles:
    active: @package.environment@

新建application-dev.yml文件 （我们只用一个环境，暂时不建立test和prod的yml文件），切换选择profiles，就会选取不同的yml文件内容，如切换dev，就会读取application-dev.yml配置文件内容

 profiles就是刚刚添加到pom.xml的配置

 application-dev.yml 添加数据库连接配置，内容如下

server.port: 15022
spring:
  devtools.restart.enabled: true  #设置开启热部署  
  freemarker.cache: false    #页面不加载缓存，修改即时生效，生产时改为true
  datasource:
      driver-class-name: com.mysql.cj.jdbc.Driver
      url: jdbc:mysql://localhost:3306/message?useUnicode=true&characterEncoding=UTF-8&serverTimezone=GMT%2B8&allowMultiQueries=true
      username: root
      password: root
      type: com.alibaba.druid.pool.DruidDataSource
      filters: stat
      maxActive: 20
      initialSize: 1
      maxWait: 60000
      minIdle: 1
      timeBetweenEvictionRunsMillis: 60000
      minEvictableIdleTimeMillis: 300000
      validationQuery: select 1
      testWhileIdle: true
      testOnBorrow: false
      testOnReturn: false
      poolPreparedStatements: true
      maxOpenPreparedStatements: 20

#Mybatis配置
#控制台打印sql
mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

二.建立package，controller（接口）、dao.mapper（mybaits-plus对应的mapper）、entity（对应DB的实体）、service和service.impl

 

1.SYS_Message表数据如下

Message对应的Entity

package com.example.demo.entity;

import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;

import java.io.Serializable;

@TableName("SYS_Message")
@Data
public class Message implements Serializable {

    /**
     * 消息id
     */
    private String msgid;

    /**
     * 消息标题
     */
    private String msgtitle;

    /**
     * 消息内容
     */
    private String msgbody;
}

 2.Mapper 需要增加注解@Mapper和@Repository,集成BaseMapper,Message为Entity

package com.example.demo.dao.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.demo.entity.Message;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

@Mapper
@Repository
public interface MessageMapper extends BaseMapper {
}

3.IMessageService 定义接口，增加接口getMessage

 

package com.example.demo.service;
import com.example.demo.entity.Message;
import java.util.List;

public interface IMessageService {

    /***
     * 获取所有消息
     * @return List
     */
    List getMessage();
}

4.MessageServiceImpl类，实现IMessageService，并继承ServiceImpl

package com.example.demo.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.example.demo.dao.mapper.MessageMapper;
import com.example.demo.entity.Message;
import com.example.demo.service.IMessageService;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class MessageServiceImpl extends ServiceImpl implements IMessageService  {
    /**
     * 获取所有消息
     * @return List
     */
    @Override
    public List getMessage() {
       return this.list();
    }
}

5.Controller实现内容：

package com.example.demo.controller;

import com.example.demo.entity.Message;
import com.example.demo.service.IMessageService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("api/message")
public class MessageController {

    @Autowired
    private IMessageService iMessageService;

    /**
     * 获取消息列表
     * @return List
     */
    @RequestMapping(value = "/all", method = RequestMethod.GET)
    public List gettestData() {
        return  iMessageService.getMessage();
    }
}

成果演示

测试请求接口​​​​​​http://localhost:15022/api/message/all

返回接口数据如下：

由此项目就搭建完成了。