Java Networking Blocking methods and while loop

Question

I made a simple UDP server/client system for my game now. This is the code of the method that waits for data to be sent to it:

while (handler.isRunning()) {
    byte[] data = new byte[1024];
    DatagramPacket packet = new DatagramPacket(data,   data.length);
    try {
        socket.receive(packet);
    } catch (IOException e) {
         e.printStackTrace();
    }
    System.out.println("Server - " + new String(data).trim());

}
socket.close();

So, the thing is, when the game closes meaning that isRunning() gets set to false, all threads die except the server and client. The reason is because here, socket.receive() method blocks and it needs to receive at least one more packet to then check if isRunning() is true and exit. So after I close the game, I want this thread to die immediately without receiving anymore packets, but i dont know how to do that! Thanks for help

score 2 · Accepted Answer · answered Dec 28 '17 at 15:57

2

There's a couple of options. First, the simplest option is to set a timeout: https://docs.oracle.com/javase/7/docs/api/java/net/DatagramSocket.html#setSoTimeout(int).

Next, another option is to use callbacks and Async I/O. Take a look at java.nio.channels.DatagramChannel

answered Dec 28 '17 at 15:57

Jonathan S. Fisher

8,189
6
46
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Thanks. But I still have a question. Do i need to set a timeout every time after i receive a packet or i do it just once? – Joza100 Dec 28 '17 at 16:00
I figured it out! – Joza100 Dec 28 '17 at 16:15

score 1 · Answer 2 · answered Dec 28 '17 at 16:03

1

Answered here. Similar for your case for DatagramSocket.receive

answered Dec 28 '17 at 16:03

ichantz

298
3
11

But the problem here is that I can't call close from any other place. It would just make my whole code unorganized. But the other answer told me to use the timeout so I will use the timeouts! Thanks for this answer anyways! – Joza100 Dec 28 '17 at 16:06

Java Networking Blocking methods and while loop

2 Answers2