Spring Boot中防表单重复提交以及拦截器登录检测

目录

 

 

理论

演示

源码

---

 

理论

在用户登录后，如果按F5刷新会出现表单重复提交的问题，解决这个问题后，如果没有拦截器登录检测，就会造成，任意用户可以登录后台界面，所以要有拦截器登录检测。

相关的逻辑步骤：

          1. 通过视图映射。把用户登录成功的界面重定向到success的界面；

          2. 创建一个HandlerInterceptor的子类，用于拦截设置；

          3. 在WebMvcConfigurerAdapter的子类中，设置拦截器，以及放行该放行的请求；

 

演示

未登录的用户直接登录后台界面：

输入用户密码登录后！

按下F5也不会出现表单重复提交的问题！

 

源码

程序结构如下：

源码如下：

LoginHandlerInterceptor.java

package firstlogindemo.demo.config;


import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/***
 * 登录检测
 */
public class LoginHandlerInterceptor implements HandlerInterceptor {

    //目标方法执行以前
    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {

        Object user = httpServletRequest.getSession().getAttribute("loginUser");
        if(user == null){

            //未登录返回登录界面
            httpServletRequest.setAttribute("msg", "没有权限请先登录");
            httpServletRequest.getRequestDispatcher("index.html").forward(httpServletRequest, httpServletResponse);
            return false;
        }

        return true;
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {

    }
}

myMvcConfig.java

package firstlogindemo.demo.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;


@Configuration
public class MyMvcConfig extends WebMvcConfigurerAdapter {

    //所有的WebMvcConfigureAdapterregistry组建都会其作用
    @Bean   //将组建注册到容器中
    public WebMvcConfigurerAdapter webMvcConfigurerAdapter(){

        WebMvcConfigurerAdapter adapter = new WebMvcConfigurerAdapter() {
            @Override
            public void addViewControllers(ViewControllerRegistry registry) {

                registry.addViewController("/").setViewName("index");
                registry.addViewController("index.html").setViewName("index");
                registry.addViewController("/main.html").setViewName("success");
            }

            //注册拦截器
            @Override
            public void addInterceptors(InterceptorRegistry registry) {

                //Spring Boot中已经做好静态资源映射
                registry.addInterceptor(new LoginHandlerInterceptor()).addPathPatterns("/**")
                        .excludePathPatterns("/index.html", "/", "/user/login");
            }
        };

        return adapter;
    }
}

LoginController.java

package firstlogindemo.demo.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.thymeleaf.util.StringUtils;

import javax.servlet.http.HttpSession;
import java.util.Map;

@Controller
public class LoginController {

    //@DeleteMapping
    //@PutMapping
    //@GetMapping
    //@RequestMapping(value = "/usr/login", method = RequestMethod.POST)

    @PostMapping(value = "/user/login")
    public String login(@RequestParam("username") String username,
                        @RequestParam("password") String password,
                        Map map, HttpSession session){

        if(!StringUtils.isEmpty(username) && "123456".equals(password)){

            //防止表单重复提交，可以重定向到主页
            //return "success";
            session.setAttribute("loginUser", username);
            return "redirect:/main.html";
        }

        map.put("msg", "用户名密码错误");
        return "index";
    }
}

index.html

    
    




    

    
用户名：
    
密  码：
    提交

success.html

    
    


[[${session.loginUser}]]
成功

application.properties

spring.thymeleaf.cache=false

porn.xml

    4.0.0
    
        org.springframework.boot
        spring-boot-starter-parent
        1.5.19.RELEASE
         
    
    com.loginWebDemo
    demo
    0.0.1-SNAPSHOT
    loginWeb
    Demo project for Spring Boot

    
        1.8
        3.0.9.RELEASE
        2.2.2
    

    
        
            org.springframework.boot
            spring-boot-starter-web
        

        
            org.springframework.boot
            spring-boot-starter-test
            test
        

        
            org.springframework.boot
            spring-boot-starter-web
        

        
            org.springframework.boot
            spring-boot-starter-thymeleaf
        

        
        
            org.webjars
            jquery
            3.3.1
        

        
        
            org.webjars
            bootstrap
            4.0.0
        

    

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