spring boot 入门

IDE：idea、DB：mysql

新建一个Spring Initializr项目

 完成后的目录结构（

DemoApplication：启动入口函数；application.properties系统配置；pox.xml系统依赖）

   4.0.0
   
      org.springframework.boot
      spring-boot-starter-parent
      2.6.3
       
   
   com.example
   demo
   0.0.1-SNAPSHOT
   demo
   Demo project for Spring Boot
   
      11
   
   
      
         org.springframework.boot
         spring-boot-starter-jdbc
      
      
         org.springframework.boot
         spring-boot-starter-thymeleaf
      
      
         org.springframework.boot
         spring-boot-starter-web
      
      
         org.mybatis.spring.boot
         mybatis-spring-boot-starter
         2.2.1
      

      
         mysql
         mysql-connector-java
         runtime
      
      
         org.springframework.boot
         spring-boot-starter-test
         test
      
   

   
      
         
            org.springframework.boot
            spring-boot-maven-plugin
         
      
   

 配置application.yaml

然后开始创建实体类实现业务流程

创建包controller、entity、mapper、service。resources下创建mapping文件夹，用于写sql语句，也可以用注解的方式直接写在mapper文件里。

 然后浏览器中出现以下：http://localhost:8080/test/index

 表示spring boot 基本配置成功。可以开始业务的编写了。

数据库表结构

CREATE TABLE `usertable` (
  `id` int NOT NULL AUTO_INCREMENT COMMENT 'id',
  `userName` varchar(32) NOT NULL COMMENT '姓名',
  `passWord` varchar(100) NOT NULL COMMENT '密码',
  `realName` varchar(100) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8mb3

建好表，插入2条数据。

 项目的目录结构：

 User.java

package com.example1.demo.entity;

import java.io.Serializable;

public class User implements Serializable {
    private Integer id;
    private String userName;
    private String passWord;
    private String realName;

    public User() {
    }

    public User(Integer id, String userName, String passWord, String realName) {
        this.id = id;
        this.userName = userName;
        this.passWord = passWord;
        this.realName = realName;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getPassWord() {
        return passWord;
    }

    public void setPassWord(String passWord) {
        this.passWord = passWord;
    }

    public String getRealName() {
        return realName;
    }

    public void setRealName(String realName) {
        this.realName = realName;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", userName='" + userName + ''' +
                ", passWord='" + passWord + ''' +
                ", realName='" + realName + ''' +
                '}';
    }
}

UserMapper.java

package com.example1.demo.mapper;


import com.example1.demo.entity.User;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface UserMapper {

    User Sel(int id);

    int Update(int id);

    int Insert(String realName);

    int Delete(int id);

    List getAll();
}

UserMapper.xml

    
        
        
        
        
    

    
        select * from userTable where id = #{id}
    

    
        update userTable set passWord = '123qwe' where id = #{id}
    

    
        insert into userTable(userName,passWord,realName) value('admin12','56494126',#{realName})
    

    
        delete from userTable where id = #{id}
    

    
        select * from userTable
    

UserService.java

import com.example1.demo.entity.User;
import com.example1.demo.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;


@Service
public class UserService {
    @Autowired
    private UserMapper userMapper;
    public User Sel(int id){
        return userMapper.Sel(id);
    }

    public int Update(int id){
        return userMapper.Update(id);
    }

    public int Insert(String realName){
        return userMapper.Insert(realName);
    }

    public int Delete(int id){
        return userMapper.Delete(id);
    }

    public List getAll(){
        return userMapper.getAll();
    }
}

UserController.java

package com.example1.demo.controller;


import com.example1.demo.entity.User;
import com.example1.demo.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("/testBoot")
public class UserController {
    @Autowired
    private UserService userService;

    @RequestMapping("/getUser/{id}")
    public String GetUser(@PathVariable int id){
        return userService.Sel(id).toString();
    }

    @RequestMapping("/update/{id}")
    public int Update(@PathVariable int id){
        return userService.Update(id);
    }

    @RequestMapping("/insert/{realName}")
    public int Insert(@PathVariable String realName){
        return userService.Insert(realName);
    }

    @RequestMapping("/delete/{id}")
    public int Delete(@PathVariable int id){
        return userService.Delete(id);
    }

    @RequestMapping("/getAll")
    public List getAll(){
        return userService.getAll();
    }

}

最终框架结构

完成以上，下面在启动类里加上注解用于给出需要扫描的mapper文件路径

最后启动，浏览器输入地址看看吧：http://localhost:8080/testBoot/getUser/1测试成功，就这样基本框架就搭建成功了。