Question

您好我正在尝试使用多个客户端实现服务器操作问题是服务器没有从输入流接收消息并等到它发生。如果客户端在写入后没有关闭流，服务器将继续等待。客户端发送消息后，他尝试从输入流中读取等待响应，但服务器正在等待请求。所以..死锁

这是我的客户端类

public class Client implements Runnable{

...

@Override
public void run() {

    BufferedReader is = null;
    BufferedWriter os = null;

    try(Socket socket = new Socket(address.getHostName(), address.getPort());){

        String request = String.format("%s-%d-%s",this.destination, this.desiredPlace, this.paymentMethod.toString());
        os = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
        is = new BufferedReader(new InputStreamReader(socket.getInputStream()));

        PrintWriter pw = new PrintWriter(os, true);
        pw.write(request);
        pw.flush();
// if I close the stream here the request will be send, but this will close the socket so the I will not receive response.

        String response;
        while ((response = is.readLine()) != null){
            System.out.println(response);
        }

    } catch (UnknownHostException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

}

这是我的服务器类

 public void perform() throws IOException, DestionationProcessingException, InterruptedException {
    try (ServerSocket server = new ServerSocket(port);) {
        StandalonePayDesk offLinePayDesk = new StandalonePayDesk(ticketManager);
        this.threadPool.submit(offLinePayDesk);

        while (true) {
            Socket socket = server.accept();
            RequestHandler handler = new RequestHandler(this.threadPool, offLinePayDesk, this.ticketManager);
            handler.process(socket);
        }
    }
}

和RequestHandler类用于处理每个客户端

try (BufferedReader reader = new BufferedReader(new InputStreamReader(client.getInputStream()));
            PrintWriter writer = new PrintWriter(client.getOutputStream(), true)) {

        writer.println("hello");
        writer.flush();

        String line;
        while ((line = reader.readLine()) != null) {

            String[] lineTokens = line.split("-");
              ...

任何人都可以帮我解决这个问题吗？

Answer 1

pw.write(request);

您的客户正在撰写请求但不是一行。您的服务器正在使用readLine()读取一行，并将阻塞直到行终止符到达，这是永远不会发生的，因此它永远不会发送回复，因此您的客户端永远不会收到它，因此它将永远阻止。 / p>

将上述内容更改为：

pw.println(request);

Java Socket Communication＆＃34; deadlock＆＃34;

1 个答案: