防止服务器在客户端（golang）服务器（Java）应用程序中终止

Question

I have a simple echo-server in Java:

 int portNumber = 4444;

    try (
        ServerSocket serverSocket =
            new ServerSocket(Integer.parseInt(args[0]));
        Socket clientSocket = serverSocket.accept();     
        PrintWriter out =
            new PrintWriter(clientSocket.getOutputStream(), true);                   
        BufferedReader in = new BufferedReader(
            new InputStreamReader(clientSocket.getInputStream()));
    ) {
        String inputLine;
        while ((inputLine = in.readLine()) != null) {
            out.println(inputLine);
            System.out.println(inputLine);
        }
    } catch (IOException e) {
        System.out.println("Exception caught when trying to listen on port "
            + portNumber + " or listening for a connection");
        System.out.println(e.getMessage());
    }

and a simple golang client:

func main() {
    fmt.Println("start client")
    conn, err := net.Dial("tcp", "localhost:4444")
    if err != nil {
        log.Fatal("Connection error", err)
    }
    conn.Write([]byte("hello world"))
    conn.Close()
    fmt.Println("done")
}

When I start the server and then run the client, the server echo's "hello world" as expected but then the server exits/terminates.

Q. How do I prevent this Java termination and force the server to continually wait for more client requests?

Answer 1

When the client terminates, the readLine on server side will result in the end of the stream. So if you want the server to continuously listen for new connections the simply put the above server code in a endless loop.

e.g.

while (true) {
   // above code
}

For a play application that would be adequate.