Question

我的应用程序中有一个TCP客户端和一个TCP服务器类。客户端发送小字符串，如“1 | 2 |”或“1 | 11 |”

客户端类

recyclerView.overScrollMode = View.OVER_SCROLL_NEVER

}

服务器类

public class TcpClient {


private static final int MAX_DATA_RETRY = 1;
private static final int PING_TIMEOUT = 100;

private ClientThread thread;
private boolean mRun = true;
private PrintWriter mBufferOut;

private String mIPAdress;


private ArrayList<BufferDataItem> messageBuffer = new ArrayList<BufferDataItem>();
private Socket mSocket;

public TcpClient()
{
    thread = new ClientThread();
    thread.start();
}

private class ClientThread extends Thread {

    @Override
    public void run() {

        while(mRun)
        {
            if(messageBuffer.size() <= 0)
                continue;

            BufferDataItem currMessage = messageBuffer.get(0);
            currMessage.retryCount++;
            if(currMessage.retryCount > MAX_DATA_RETRY)
            {
                messageBuffer.remove(0);
                continue;
            }

            try {
                //here you must put your computer's IP address.
                InetAddress serverAddr = InetAddress.getByName(currMessage.ip);



                //Log.e("TCP Client", "C: Connecting...");

                try {
                    if(!serverAddr.isReachable(PING_TIMEOUT))
                    {
                        //only attempt to connect to devices that are reachable
                        messageBuffer.remove(0);
                        continue;
                    }


                    //create a socket to make the connection with the server
                    mSocket = new Socket(serverAddr, TcpManager.SERVER_PORT);

                    //Log.i("TCP Debug", "inside try catch");
                    //sends the message to the server

                    mBufferOut = new PrintWriter(new BufferedWriter(new OutputStreamWriter(mSocket.getOutputStream())), true);

                    String message = currMessage.message;
                    if (mBufferOut != null && !mBufferOut.checkError()) {
                        Log.d("TCP SEND", "PUTTING IN BUFFER!  " + message);
                        mBufferOut.println(message);
                        listener.messageSent(message, currMessage.ip);
                        messageBuffer.remove(0);
                    }
                    mBufferOut.flush();

                }
                catch (ConnectException e) {
                    //Connection refused by found device!
                    //Log.e("TCP", "C: ConnectException   ip = "+currMessage.ip, e);
                    listener.hostUnreachable(currMessage.ip);
                    continue;
                }
                catch (Exception e) {
                    Log.e("TCP", "S: Error", e);
                    listener.messageSendError(e);
                }
                finally {
                    if(mSocket != null)
                        mSocket.close();
                }

            }
            catch (Exception e) {
                Log.e("TCP", "C: Error", e);
                listener.messageSendError(e);
                continue;
            }
        }
    }
}



/**
 * Sends the message entered by client to the server
 *
 * @param message text entered by client
 */
public void sendMessage(String message) {

    BufferDataItem data = new BufferDataItem();
    data.message = message;
    data.ip = mIPAdress;
    messageBuffer.add(data);
}

public void sendMessage(String message, String ip) {
    mIPAdress = ip;
    BufferDataItem data = new BufferDataItem();
    data.message = message;
    data.ip = mIPAdress;
    messageBuffer.add(data);
}


/**
 * Close the connection and release the members
 */
public void stopClient() {
    Log.i("Debug", "stopClient");

    mRun = false;

    if (mBufferOut != null) {
        mBufferOut.flush();
        mBufferOut.close();
    }
    mBufferOut = null;
}

private class BufferDataItem
{
    public String message = "";
    public int retryCount = 0;
    public String ip = "";
}

private OnMessageSent listener = null;

public interface OnMessageSent {
    public void messageSent(String message, String ip);

    public void hostUnreachable(String ip);

    public void messageSendError(Exception e);

}

public void setMessageSentListener(OnMessageSent listener)
{
    this.listener = listener;
}

public void removeMessageSentListener()
{
    this.listener = null;
}

}

这在运行的前几次运行正常然后客户端发送“1 | 11 |”并且服务器在readLine期间将st设置为null。 String st = input.readLine（）;

有人有任何建议吗？

Answer 1

我看到服务器在一段时间后没有收到有效数据的两个可能原因。

服务器不会关闭套接字s，因为mEnd永远不会设置为true。客户端为每条消息打开一个新的TCP连接。服务器为连接创建一个套接字，但它从不关闭套接字，并且连接的服务器端保持打开状态。这是资源泄漏，可能会导致问题。
客户端使用ArrayList<BufferDataItem> messageBuffer。 ArrayList不是线程安全集合，messageBuffer来自多个线程。在这里使用synchronizedList是安全的。请参阅How do I make my ArrayList Thread-Safe? Another approach to problem in Java?或Concurrent threads adding to ArrayList at same time - what happens?

TCP客户端发送数据但TCP服务器接收空值

1 个答案: