Java Sockets - 挂起从服务器读取数据

Question

我目前正在使用套接字执行一个小的客户端/服务器任务。遗憾的是，当客户端应该读取服务器发送的“200 OK File Created”时，客户端挂起。有什么是我忽略的吗？

客户:

public HTTPClient(InetAddress adress, int portnumber, String filename) throws IOException {
    socket = new Socket(adress, portnumber);
    input = new BufferedReader(new InputStreamReader(socket.getInputStream()));
    output = new PrintWriter(socket.getOutputStream());
    this.filename = filename;
}

public void sendPutRequest() throws IOException {
    output.println("PUT /" + filename + " HTTP/1.0");
    output.flush();
    File myFile = new File(this.filename);
    if (myFile.exists()) {
        for (String string : Files.readAllLines(myFile.toPath())) {
            output.println(string);
        }
        output.flush();
        String line;
        while ((line = input.readLine()) != null) {
            System.out.println(line);
        }
    } else {
        throw new IOException("File not found");
    }
}

服务器:

  try (Socket client = this.socket.accept(); 
    BufferedReader in = new BufferedReader(
    new InputStreamReader(client.getInputStream()));
    PrintWriter out = new PrintWriter(client.getOutputStream())) {

    String lineIn = in.readLine();
    if (lineIn.contains("PUT")) {
        String filename = lineIn.split(" ")[1].substring(1);
        List<String> filedata = new ArrayList<>();
        String line;
        while ((line = in.readLine()) != null) {
            filedata.add(line);
            System.out.println(line);
        }
        writeToFile(filename, filedata);
        out.println("200 OK File Created");
        out.flush();
    }
}

Answer 1

您的服务器正在从连接中读取数据，直到连接关闭为止(仅在这种情况下，in.readLine() 才会返回 null)。

但是您的客户端不会关闭与服务器的连接。因此服务器陷入了 while 循环。

解决方案:发送请求后必须关闭output流。或者，在服务器端检测请求的结束，而无需等待“流结束”限制。