一个简单的SpringBoot项目 demo

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架构

相关代码

templates目录下存放前端静态页面

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>hello</title>
</head>
<body>
	SpringBoot的简单启动页面!
</body>
</html>

error.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>error</title>
</head>
<body>
<h1>登录失败!</h1>
</body>
</html>

login.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="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>

success.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>success</title>
</head>
<body>
<h1>登录成功!</h1>
</body>
</html>

拦截器contronller

HelloController.java

package com.example.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class HelloController 
    @RequestMapping("/index")
    public String sayHello()
        return "index";
    



LoginController.java
添加@controller注解,注入Service服务

package com.example.controller;

import com.example.bean.UserBean;
import com.example.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;

@Controller
public class LoginController 

    //将Service注入Web层
    @Autowired
    UserService userService;

    @RequestMapping("/login")
    public String show()
        return "login";
    

    @RequestMapping(value = "/loginIn",method = RequestMethod.POST)
    public String login(String name,String password)
        UserBean userBean = userService.loginIn(name,password);
        if(userBean!=null)
            return "success";
        else 
            return "error";
        
    


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。

bean层:
UserBean.java

package com.example.bean;

import lombok.Data;

@Data
public class UserBean 
    private int id;
    private String name;
    private String password;


service目录
UserService.java

package com.example.service;

import com.example.bean.UserBean;

public interface UserService 
    UserBean loginIn(String name, String password);


serviceImpl目录:
UserServiceImpl.java

package com.example.serviceImpl;

import com.example.bean.UserBean;
import com.example.mapper.UserMapper;
import com.example.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class UserServiceImpl implements UserService 

    //将DAO注入Service层
    @Autowired
    private UserMapper userMapper;

    @Override
    public UserBean loginIn(String name, String password) 
        return userMapper.getInfo(name,password);
    



mapper目录:
UserMapper.java

package com.example.mapper;

import com.example.bean.UserBean;

//DAO层访问数据库接口文件:
public interface UserMapper 
    UserBean getInfo(String name, String password);


resources–>mapper
UserMapper.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.example.mapper.UserMapper">

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

</mapper>

<!--
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<mapper>标签的namespace属性要填写 访问数据库接口类文件路径。-->

YanjingMallApplication.java

package com.example;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan("com.example.mapper")
@SpringBootApplication
public class YanjingMallApplication 

    public static void main(String[] args) 
        SpringApplication.run(YanjingMallApplication.class, args);
    



application.yml


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

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

pom.xml

<?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 https://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>2.6.6</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>Yanjing-mall</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>Yanjing-mall</name>
    <description>Yanjing-mall</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <!--thymeleaf模板引擎配置-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <!--Web依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--MyBatis配置-->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.2</version>
        </dependency>

        <!--MySQL数据库配置-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <!--单元测试配置-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- lombok配置 不需要加get set方法-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>RELEASE</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-test</artifactId>
            <version>2.6.6</version>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>5.3.18</version>
            <scope>compile</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

小结:
前端输入:http://localhost:8080/login

输入信息登录点击login -> 提交loginIn表单,浏览器 访问http://localhost:8080/loginIn
后端代码调用userService对象的loginIn方法,然后调用dao层的usermapper的getInfo方法查询输入的用户信息数据库中是否存在,存在跳转至success界面,反之跳转到error !

JAVA目录

src下main:存放的是代码源文件,java、xml、proeprties等

src下test:通常是我们做单元测试的时候使用

controller:此目录主要是存放Controllerde ,比如:UserController.java,也有的项目是把action放在controller目录下,有的是把UserController.java放在action目录下。

service:这里分接口和实现类,接口在service目录下,接口实现类在service/impl目录下。

dao:持久层,目前比较流行的Mybatis或者jpa之类的。
mapper: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)

entity:就是数据库表的实体对象。
Bean: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;

interrupt:项目统一拦截处理,比如:登录信息,同意异常处理

config:配置读取相关,比如RedisConfig.java

resources目录

static:存放的是一些js/css/图片

templates:存放模板引擎文件,比如:user.fl

application.properties文件是存放一些配置文件,有的是application.yml或者application.yaml实质是一样的,就是展示不同而已。

mapper: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。

参考:
https://blog.csdn.net/baidu_39298625/article/details/98102453
https://blog.csdn.net/sinat_27933301/article/details/88563560

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