用springboot写一个简单的web登录页面

2022-06-28 10:49:25

前言

先简单建一个springboot项目试试,看看运行以后,localhost:8080能否进入,还有maven包是否已经导入。

springboot介绍:
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项目目录

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具体实现

1.按照目录,依次将包建好,我的项目名叫test。
2.bean包内建立“Userbean”

package com.example.test.bean;publicclassUserBean{privateint id;private String name;private String password;publicintgetId(){return id;}publicvoidsetId(int id){this.id= id;}public StringgetName(){return name;}publicvoidsetName(String name){this.name= name;}public StringgetPassword(){return password;}publicvoidsetPassword(String password){this.password= password;}}

3.controller包内建立"LoginController"

package com.example.test.controller;import com.example.test.bean.UserBean;import com.example.test.service.UserService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;@ControllerpublicclassLoginController{//将Service注入Web层@Autowired
    UserService userService;@RequestMapping("/login")public Stringshow(){return"login";}@RequestMapping(value="/loginIn",method= RequestMethod.POST)public Stringlogin(String name,String password){
        UserBean userBean= userService.loginIn(name,password);if(userBean!=null){return"success";}else{return"error";}}}

4.mapper文件夹下建立"Usermapper"(DAO层访问数据库接口文件: )

package com.example.test.mapper;import com.example.test.bean.UserBean;publicinterfaceUserMapper{

    UserBeangetInfo(String name,String password);}

5.service文件夹下建立"Userservice"(Service层业务实现类编写,注意要注解@Service,注入DAO)

package com.example.test.service;import com.example.test.bean.UserBean;publicinterfaceUserService{

    UserBeanloginIn(String name,String password);}

6.ServiceImpl文件夹下建立"UserServiceImpl"

package com.example.test.serviceImpl;import com.example.test.bean.UserBean;import com.example.test.mapper.UserMapper;import com.example.test.service.UserService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;@ServicepublicclassUserServiceImplimplementsUserService{//将DAO注入Service层@Autowiredprivate UserMapper userMapper;@Overridepublic UserBeanloginIn(String name, String password){return userMapper.getInfo(name,password);}}

7.启动java的TestApplication(项目启动类要添加注解@MapperScan项目启动时扫描mapper接口,否则会报错找不到mapper文件)

package com.example.test;import org.mybatis.spring.annotation.MapperScan;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplication@MapperScan("com.example.test.mapper")publicclassTestApplication{publicstaticvoidmain(String[] args){
        SpringApplication.run(TestApplication.class, args);}}

8.在下面的resources文件夹下要再建立一个mapper文件夹,里面建立Usermapper.xml(xml第一行不能空,不然会报错)

(DAO层访问数据库实现文件(需在resource包下创建mapper文件夹,然后再创建一个UserMapper.xml.在application配置文件中mybatis:mapper-locations:对应的就是该文件地址),注意标签的namespace属性要填写 访问数据库接口类文件路径:)

<?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.example.test.mapper.UserMapper"><select id="getInfo" parameterType="String" resultType="com.example.test.bean.UserBean">
        SELECT* FROM user WHERE name= #{name} AND password= #{password}</select></mapper>

9.下面的application.yml如果不是yml格式,可以先右键Refactor然后Rename修改为yml格式
然后代码如下:(url都是一样的,不同于在你的数据库名,用户名和密码基本都是root,123456,不过也得看你自己的。数据库驱动一定要加,如果报错,更新maven包试试)

spring:
  datasource:
    name: test  #数据库名
    url: jdbc:mysql://localhost:3306/test #url
    username: root  #用户名
    password:123456  #密码
    driver-class-name: com.mysql.jdbc.Driver  #数据库链接驱动


mybatis:
  mapper-locations: classpath:mapper/*.xml  #配置映射文件
  type-aliases-package: com.example.test.bean #配置实体类

10.最后在temlplates添加login.html success.html error.html 即可

<!DOCTYPE html><htmllang="en"><head><metacharset="UTF-8"><title>login</title></head><body>
<form role="form" action = "/loginIn" method="post">
    账号:<input type="text" id="name" name = "name"><br>
    密码:<input type="password" id = "password" name = "password"><br>
    <input type="submit" id = "login" value = "login"></form></body></html>
<!DOCTYPE html><htmllang="en"><head><metacharset="UTF-8"><title>success</title></head><body><h1>登录成功!</h1></body></html>
<!DOCTYPE html><htmllang="en"><head><metacharset="UTF-8"><title>error</title></head><body><h1>登录失败!</h1></body></html>

总结:

SpringBoot项目大概分为四层:

(1)DAO层:包括XxxMapper.java(数据库访问接口类),XxxMapper.xml(数据库链接实现);(这个命名,有人喜欢用Dao命名,有人喜欢用Mapper,看个人习惯了吧)

(2)Bean层:也叫model层,模型层,entity层,实体层,就是数据库表的映射实体类,存放POJO对象;

(3)Service层:也叫服务层,业务层,包括XxxService.java(业务接口类),XxxServiceImpl.java(业务实现类);(可以在service文件夹下新建impl文件放业务实现类,也可以把业务实现类单独放一个文件夹下,更清晰)

(4)Web层:就是Controller层,实现与web前端的交互

最后附上学习的博主文章(写的是真滴好)
https://blog.csdn.net/baidu_39298625/article/details/98102453?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-4.control&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromMachineLearnPai2-4.control

  • 作者:Cabbage coder
  • 原文链接:https://blog.csdn.net/weixin_45678130/article/details/112568830
    更新时间:2022-06-28 10:49:25