setSotimeout on a datagram socket

Question

The server acts like an echo server. The clients sends 10 packets to server (1 sec of gap)

When Client receives packets from the server, sometimes the packets are lost.

Answer 1

The javadoc for setSoTimeout says:

With this option set to a non-zero timeout, a call to receive() for this DatagramSocket will block for only this amount of time. If the timeout expires, a java.net.SocketTimeoutException is raised, though the DatagramSocket is still valid.

So, if you want to send packets if no response has been received after 1 second, you just have to use

socket.setSoTimeout(1000L);
boolean continueSending = true;
int counter = 0;
while (continueSending && counter < 10) {
    // send to server omitted
    counter++;
    try {
        socket.receive(packet);
        continueSending = false; // a packet has been received : stop sending
    }
    catch (SocketTimeoutException e) {
        // no response received after 1 second. continue sending
    }
}