TCP android 服务器未收到来自 Java TCP 客户端的第一条消息

Question

我在 java 中有一个 TCP 客户端，在 android 中有一个 TCP 服务器。将消息从服务器发送到客户端工作正常但是当消息从客户端发送到服务器时（android）它不显示消息但是当第二次重复相同的过程时，服务器显示消息即[=的发送按钮24=] 客户端应按两次，然后 android 应用程序中只显示消息。

Java 客户端代码

//btn handelar to send message form textarea
private class ButtonHandler implements ActionListener
{
    public void actionPerformed (ActionEvent event)
    {
        String outputLine = txArea.getText ();
        System.out.println ("Client > " + outputLine);
        out.println (outputLine);
        out.flush();


    }
}

   //receiving message
public void run () throws IOException
{
    Socket socket = new Socket ("192.168.123.3",1234);
    BufferedReader in = new BufferedReader (new InputStreamReader (socket.getInputStream ()));
    out = new PrintWriter (socket.getOutputStream (), true);

    String inputLine;

    while ((inputLine = in.readLine ()) != null)
    {
        System.out.println ("Client <  " + inputLine);
        rxArea.setText (inputLine);
    }


    out.close();
    in.close();
    socket.close();
}

Android 服务器代码

 public void runTcpServer(){

    handel = new Handler();
    try {

        int a = Integer.parseInt(new SettingDialog().port);
        //creating a socket to listen on a given port
        Log.i("NW LOG","PORT OPENED SUCESSFULLY in "+a);
        final ServerSocket serverSocket = new ServerSocket(a);

        Thread listenConnection = new Thread(new Runnable() {
            @Override
            public void run() {

                try {

                    //accepting the incoming socket connection request
                    Socket workstationSocket = serverSocket.accept();
                    //reading the incoming content
                   BufferedReader  readerIn = new BufferedReader(new InputStreamReader(workstationSocket.getInputStream()));

                   outMessage = new PrintStream(workstationSocket.getOutputStream(),true);


                    Log.i("NW LOG","WATING FOR MSG");
                    while(readerIn.readLine()!=null){

                        final String incomingMsg = readerIn.readLine();

                        //setting incoming message to UI thread using handler
                        handel.post(new Runnable() {
                            @Override
                            public void run() {
                                setMessage(IN,incomingMsg);
                            }
                        });


                    }
                    outMessage.close();
                    readerIn.close();
                    workstationSocket.close();
                    serverSocket.close();



                } catch (IOException e) {
                    e.printStackTrace();
                }


            }
        });listenConnection.start();

    } catch (IOException e) {
        e.printStackTrace();
    }


}

Answer 1

问题出在以下代码部分：

while(readerIn.readLine()!=null){
    final String incomingMsg = readerIn.readLine();
    ....

在第一行中，您正在阅读该行并忽略它。因此，您每隔一行就扔掉一次。

在 while 循环中阅读和使用它的正确方法是：

String incomingMsg;
while((incomingMsg = readerIn.readLine())!=null){
      ....
}

TCP android 服务器未收到来自 Java TCP 客户端的第一条消息

TCP android Server not recieving first message from Java TCP client

java

sockets

android

serversocket