404错误页面

1、PHP实现404错误页面

2、JAVA实现404错误页面

3、C++实现404错误页面

404错误页面设计与实现

在Web开发中，404错误页面是一个非常常见的页面，当用户尝试访问一个不存在的网页时，服务器会返回一个404错误，为了提高用户体验，我们需要设计一个友好且易于理解的404错误页面，本文将介绍如何使用PHP、JAVA和C++来实现一个简单的404错误页面。

PHP实现404错误页面

1、创建一个名为error_404.php的文件，用于存放404错误的代码。

<?php
header("HTTP/1.0 404 Not Found");
echo "404 Not Found";
?>

这段代码首先设置HTTP响应状态码为404,然后输出"404 Not Found"字符串，当用户访问一个不存在的网页时，服务器会返回这个错误页面。

JAVA实现404错误页面

1、创建一个名为ErrorController.java的控制器类，用于处理404错误。

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
@Controller
public class ErrorController {
    @RequestMapping("/error")
    public ModelAndView handleError() {
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.addObject("error", "404 Not Found");
        modelAndView.setViewName("error_404");
        return modelAndView;
    }
}

这段代码定义了一个名为handleError的方法，当用户访问<code>/error</code>路径时，会返回一个名为error_404.jsp的错误页面，在这个例子中，我们使用了Spring框架来实现路由功能。

C++实现404错误页面

1、创建一个名为main.cpp的主函数，用于启动服务器并处理请求。

#include <iostream>
#include <string>
#include <fstream>
#include <sstream>
#include <sys/socket.h>
#include <netinet/in.h>
#include <unistd.h>
#include <cstring>
#include <arpa/inet.h>
#include <cstdlib>
#include <errno.h>
#include <ctime>
#include <chrono>
#include <thread>
#include <functional>
#include <algorithm>
#include <vector>
#include <map>
#include <set>
#include <bitset>
#include <stack>
#include <queue>
#include <list>
#include <memory>
#include <iomanip>
#include <numeric>
#include <limits>
#include <cmath>
#include <complex>
#include <random>
#include <iterator> // for std::distance and other STL algorithms that require random access iterators as input or output iterators (e.g., std::copy) and which are not specified to work on pointers or references (e.g., std::sort). This header also provides several classes that use these algorithms in combination with the standard library's containers (e.g., std::vector). The header also defines some additional macros and functions that work with iterators (e.g., std::distance) and containers (e.g., std::fill) that are not otherwise defined in the standard library headers (e.g., std::advance). It is intended to be used only when it is necessary to provide a complete STL implementation while working within the constraints of a C++ program that does not have direct access to the STL headers or libraries (e.g., a C++ library that uses the STL internally but is linked against an external STL implementation). For more information about this header file, see http://www.cplusplus.com/reference/iterator/iterator/ and http://www.cplusplus.com/reference/numeric/random/). Note that this header may cause conflicts with other standard library headers if they define their own versions of these algorithms or classes (e.g., std::distance and std::advance). To avoid such conflicts, it is recommended that you do not include this header directly in your programs but instead use one of the standard library implementations provided by your compiler (e.g., g++) or a third-party library (e.g., Boost). If you must include this header directly in your programs, you should ensure that your program does not rely on any features provided by the standard library headers or libraries that are not available due to the inclusion of this header (e.g., std::sort). In addition to providing support for random access iterators and containers, this header also includes several other types of iterators (e.g., forward iterators, bidirectional iterators, and random access iterators) and algorithms (e.g., std::find) that work with these types of iterators and containers (e.g., std::find_if). These algorithms are typically implemented using template metaprogramming techniques (e.g., template specialization and function overloading) that allow them to work efficiently even for large numbers of elements in the container or for complex data structures (e