你能否用一个简单的Web服务器案例展示Java的ServerSocket用法

wen java案例 2026-06-05 328

本文目录导读：

简单Web服务器实现
测试用的HTML文件
使用步骤
关键概念解释

我来用一个简单的Web服务器案例展示Java的ServerSocket用法。

简单Web服务器实现

import java.io.*;
import java.net.*;
import java.nio.file.*;
import java.util.*;
public class SimpleWebServer {
    private static final int PORT = 8080;
    private static final String WEB_ROOT = "./webroot";
    public static void main(String[] args) {
        System.out.println("Simple Web Server starting on port " + PORT + "...");
        // 创建webroot目录
        new File(WEB_ROOT).mkdirs();
        try (ServerSocket serverSocket = new ServerSocket(PORT)) {
            System.out.println("Server started. Access http://localhost:" + PORT);
            while (true) {
                // 等待客户端连接
                try (Socket clientSocket = serverSocket.accept()) {
                    handleClient(clientSocket);
                } catch (IOException e) {
                    System.err.println("Error handling client: " + e.getMessage());
                }
            }
        } catch (IOException e) {
            System.err.println("Could not start server: " + e.getMessage());
        }
    }
    private static void handleClient(Socket clientSocket) throws IOException {
        String clientAddress = clientSocket.getInetAddress().getHostAddress();
        System.out.println("New connection from: " + clientAddress);
        // 获取输入输出流
        BufferedReader in = new BufferedReader(
            new InputStreamReader(clientSocket.getInputStream()));
        OutputStream out = clientSocket.getOutputStream();
        // 读取HTTP请求
        String requestLine = in.readLine();
        if (requestLine == null || requestLine.isEmpty()) {
            return;
        }
        System.out.println("Request: " + requestLine);
        // 解析请求路径
        String[] requestParts = requestLine.split(" ");
        String method = requestParts[0];
        String path = requestParts.length > 1 ? requestParts[1] : "/";
        // 处理GET请求
        if ("GET".equals(method)) {
            handleGetRequest(path, out);
        } else {
            sendResponse(out, 405, "Method Not Allowed", "405 Method Not Allowed".getBytes());
        }
        // 关闭输出流
        out.flush();
    }
    private static void handleGetRequest(String path, OutputStream out) throws IOException {
        // 默认首页
        if (path.equals("/")) {
            path = "/index.html";
        }
        File file = new File(WEB_ROOT + path);
        if (file.exists() && !file.isDirectory()) {
            // 文件存在，返回内容
            byte[] content = Files.readAllBytes(file.toPath());
            String contentType = getContentType(path);
            sendResponse(out, 200, "OK", content, contentType);
        } else {
            // 文件不存在，返回404
            String errorMessage = "<html><body><h1>404 Not Found</h1>" +
                                 "<p>The requested resource was not found.</p></body></html>";
            byte[] content = errorMessage.getBytes();
            sendResponse(out, 404, "Not Found", content, "text/html");
        }
    }
    private static void sendResponse(OutputStream out, int statusCode, 
                                    String statusMessage, byte[] content) throws IOException {
        sendResponse(out, statusCode, statusMessage, content, "text/html");
    }
    private static void sendResponse(OutputStream out, int statusCode,
                                    String statusMessage, byte[] content, 
                                    String contentType) throws IOException {
        // 构建HTTP响应
        String header = "HTTP/1.1 " + statusCode + " " + statusMessage + "\r\n" +
                       "Content-Type: " + contentType + "\r\n" +
                       "Content-Length: " + content.length + "\r\n" +
                       "Server: SimpleJavaServer/1.0\r\n" +
                       "Date: " + new Date() + "\r\n" +
                       "Connection: close\r\n" +
                       "\r\n";
        out.write(header.getBytes());
        out.write(content);
    }
    private static String getContentType(String path) {
        if (path.endsWith(".html") || path.endsWith(".htm")) {
            return "text/html";
        } else if (path.endsWith(".css")) {
            return "text/css";
        } else if (path.endsWith(".js")) {
            return "application/javascript";
        } else if (path.endsWith(".png")) {
            return "image/png";
        } else if (path.endsWith(".jpg") || path.endsWith(".jpeg")) {
            return "image/jpeg";
        } else if (path.endsWith(".gif")) {
            return "image/gif";
        } else if (path.endsWith(".txt")) {
            return "text/plain";
        } else {
            return "application/octet-stream";
        }
    }
}

测试用的HTML文件

创建 webroot/index.html:

<!DOCTYPE html>
<html>
<head>Simple Java Web Server</title>
    <style>
        body {
            font-family: Arial, sans-serif;
            margin: 40px;
            background-color: #f0f0f0;
        }
        .container {
            background-color: white;
            padding: 20px;
            border-radius: 5px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
        }
        h1 {
            color: #333;
        }
        .success {
            color: green;
        }
        .info {
            background-color: #e7f3fe;
            border-left: 6px solid #2196F3;
            padding: 10px;
            margin: 10px 0;
        }
    </style>
</head>
<body>
    <div class="container">
        <h1>Simple Java Web Server</h1>
        <p class="success">✓ 服务器运行正常！</p>
        <div class="info">
            <h2>服务器信息</h2>
            <ul>
                <li>服务器类型：SimpleJavaServer/1.0</li>
                <li>端口：8080</li>
                <li>支持的文件类型：HTML, CSS, JavaScript, 图片, 文本文件</li>
            </ul>
        </div>
        <h2>可用页面</h2>
        <ul>
            <li><a href="/">首页</a></li>
            <li><a href="/about.html">关于页面</a></li>
            <li><a href="/nonexistent.html">404测试页面</a></li>
        </ul>
        <p>当前时间：<span id="time"></span></p>
        <script>
            document.getElementById('time').textContent = new Date().toLocaleString();
        </script>
    </div>
</body>
</html>

创建 webroot/about.html:

<!DOCTYPE html>
<html>
<head>- Simple Java Web Server</title>
    <style>
        body {
            font-family: Arial, sans-serif;
            margin: 40px;
            background-color: #f0f0f0;
        }
        .container {
            background-color: white;
            padding: 20px;
            border-radius: 5px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
        }
    </style>
</head>
<body>
    <div class="container">
        <h1>关于本服务器</h1>
        <p>这是一个使用Java ServerSocket实现的简单Web服务器。</p>
        <h2>工作原理</h2>
        <ol>
            <li>使用ServerSocket监听8080端口</li>
            <li>接受客户端连接</li>
            <li>解析HTTP请求</li>
            <li>读取文件并返回HTTP响应</li>
        </ol>
        <p><a href="/">返回首页</a></p>
    </div>
</body>
</html>