因此，我创建了一个简单的服务器，它使用 ServerSocket 接受来自浏览器的连接。当浏览器连接时，它会运行一个新线程 (ClientHandler) 来处理该连接。在 clientHandler 中，它

所以我创建了一个简单的服务器，它使用 ServerSocket 接受来自浏览器的连接。当浏览器连接时，它会运行一个新线程 (ClientHandler) 来处理该连接。在 clientHandler 中，它响应 GET 请求并提交一个 html 页面。该页面只有 1 个按钮，用于发送值为“Hello from browser”的 POST 请求，这是使用 AJAX 完成的，因此页面不会刷新。每次我发送 POST 请求时，它都会与套接字建立新连接，但响应中的连接是否保持活动状态？

import java.io.*;
import java.net.*;

public class Server {
    private static final int PORT = 8080;
    private static int count = 0;
    private static final String HTML_FILE_PATH = "src/main/java/org/example/index.html";

    public static void main(String[] args) throws Exception {
        try (ServerSocket serverSocket = new ServerSocket(PORT)) {
            System.out.println("Server started on port " + PORT);

            while (true) {
                try {
                    Socket clientSocket = serverSocket.accept();
                    System.out.println("Client: " + ++count + " Joined");
                    ClientHandler clientHandler = new ClientHandler(clientSocket);
                    // Handle the client connection in a new thread 
                    new Thread(clientHandler).start();
                } catch (IOException e) {
                    System.err.println("Error accepting client connection: " + e.getMessage());
                }
            }
        }
    }
}

import java.io.*;
import java.net.*;
import java.nio.file.Files;
import java.util.concurrent.atomic.AtomicInteger;

public class ClientHandler implements Runnable {
    private static final AtomicInteger nextId = new AtomicInteger(0);
    private Socket clientSocket;
    private int clientId;
    private static final String HTML_FILE_PATH = "src/main/java/org/example/index.html";

    public ClientHandler(Socket clientSocket) {
        this.clientSocket = clientSocket;
        this.clientId = nextId.incrementAndGet();
    }

    @Override
    public void run() {
        try (BufferedReader reader = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
             BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream()))) {

            String line;
            StringBuilder requestBuilder = new StringBuilder();
            while (!(line = reader.readLine()).isBlank()) {
                requestBuilder.append(line).append("\r\n");
            }
            String request = requestBuilder.toString();
            String[] requestLines = request.split("\r\n");
            String[] requestLine = requestLines[0].split(" ");
            String method = requestLine[0];
            String path = requestLine[1];
            if ("GET".equals(method) && "/".equals(path)) {
                serveFile(HTML_FILE_PATH, writer);
            } else if ("POST".equals(method)) {
                // Extract the Content-Length from the headers
                int contentLength = getContentLength(requestLines);
                char[] buffer = new char[contentLength];

                // Read the POST data from the input stream
                reader.read(buffer, 0, contentLength);
                String postData = new String(buffer);

                // Print the POST data in the server terminal
                System.out.println("POST Data: " + postData);

                // Continue with sending the response
                String responseMessage = "Hello Client " + clientId + ", This is server.";
                writeResponse(writer, "HTTP/1.1 200 OK", "text/plain", responseMessage.getBytes(), true);
            } else {
                writeResponse(writer, "HTTP/1.1 404 Not Found", "text/plain", "Not Found".getBytes(), false);
            }
        } catch (IOException e) {
            System.err.println("Error handling client " + clientId + ": " + e.getMessage());
        }
    }

    private void serveFile(String filePath, BufferedWriter writer) throws IOException {
        File file = new File(filePath);
        if (file.exists()) {
            byte[] fileContent = Files.readAllBytes(file.toPath());
            writeResponse(writer, "HTTP/1.1 200 OK", "text/html", fileContent, true);
        } else {
            writeResponse(writer, "HTTP/1.1 404 Not Found", "text/plain", "File not found".getBytes(), false);
        }
    }

    private void writeResponse(BufferedWriter writer, String statusLine, String contentType, byte[] content, boolean keepAlive) throws IOException {
        writer.write(statusLine + "\r\n");
        writer.write("Content-Type: " + contentType + "\r\n");
        writer.write("Content-Length: " + content.length + "\r\n");
        if (keepAlive) {
            writer.write("Connection: keep-alive\r\n");
            writer.write("Keep-Alive: timeout=60, max=100\r\n");
        } else {
            writer.write("Connection: close\r\n");
        }
        writer.write("\r\n");
        writer.write(new String(content));
        writer.flush();
    }
    private int getContentLength(String[] requestHeaders) {
        for (String header : requestHeaders) {
            if (header.toLowerCase().startsWith("content-length:")) {
                return Integer.parseInt(header.substring("content-length:".length()).trim());
            }
        }
        return 0;
    }
}

<!DOCTYPE html>
<html>
<head>
    <title>Tic-Tac-Toe</title>
</head>
<body>
<button id="helloButton">Say Hello</button>
<div id="responseText"></div>
<script>
    document.getElementById('helloButton').onclick = function() {
        fetch('/', {
            method: 'POST',
            headers: {
                'Content-Type': 'text/plain'
            },
            body: 'Hello from browser'
        })
            .then(response => response.text())
            .then(data => document.getElementById('responseText').innerText = data)
            .catch(error => console.error('Error:', error));
    };
</script>
</body>
</html>

我原本期望有持久连接，但发送多个 POST 请求时的输出如下。 开发工具中的 服务器终端