我在java中設置一個簡單的TCP客戶端服務器交互.

服務器：

服務器是用Java編寫的桌面客戶端：

import java.io.BufferedReader;

import java.io.DataOutputStream;

import java.io.InputStreamReader;

import java.net.ServerSocket;

import java.net.Socket;

class TCPServer

{

public static int PORT_NUMBER = 6129;

public static void main(String argv[]) throws Exception

{

String clientMessage;

ServerSocket welcomeSocket = new ServerSocket(PORT_NUMBER);

while (true)

{

Socket connectionSocket = welcomeSocket.accept();

BufferedReader inFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));

DataOutputStream outToClient = new DataOutputStream(connectionSocket.getOutputStream());

clientMessage = inFromClient.readLine();

System.out.println("Received: " + clientMessage);

outToClient.writeBytes("I received this: "+ clientMessage +"\n");

}

}

}

客戶：

客戶端是一個Android應用程序,通過TCP連接到服務器.在客戶端我有一個方法sendMessage(String msg),它嘗試向服務器發送消息.

public static void sendMessage(String msg) throws IOException

{

if (mainSocket == null)

{

return;

}

if (!mainSocket.isConnected())

{

connectSocket();

}

PrintWriter output = new PrintWriter( mainSocket.getOutputStream());

output.println(msg);

output.flush();

System.out.println(msg);

}

問題是,服務器收到第一條消息,但任何后續消息都不會顯示.當我關閉客戶端時,所有其他消息突然出現在服務器中.

這是服務器看到的：

Received: message 1

很長一段時間都沒有活動……

然后我關閉了客戶端

Received: message 2 message 3 message 4 message 5 etc..

我在sendMessage()方法中放了一個println,并且實時調用了方法本身.

解決方法:

每次發送消息時,您都需要在客戶端顯式關閉()PrintWriter.當您完成讀取inFromClient時,在服務器端也是如此,并且當您完成寫入outToClient時再次.

另見這篇basic example,他們很好地解釋了基本的工作流程：

However, the basics are much the same as they are in this program:

Open a socket.

Open an input stream and output stream to the socket.

Read from and write to the stream according to the server’s protocol.

Close the streams.

Close the socket.

標簽：android,java,tcp

來源： https://codeday.me/bug/20190826/1734001.html

總結

以上是生活随笔為你收集整理的java tcp发消息给硬件_java – TCP客户端/服务器通信只发送第一条消息？的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。