Java network communication over UDP socket
Petr Faltus development
net_udp_receiver.java
GitHub repository: network-socket-communication-source-codes
git clone https://github.com/petrfaltus/network-socket-communication-source-codes.git
Directories to net_udp_receiver.java in the repository: java/cz/petrfaltus/net
package cz.petrfaltus.net; import java.io.IOException; import java.net.DatagramPacket; import java.net.DatagramSocket; import java.net.InetAddress; import static java.lang.System.out; public class net_udp_receiver { private static final int RECEIVER_PORT = 10000; private static final int BUFFER_SIZE = 4096; public static void main(String[] args) { out.println("UDP IPv4 datagram socket receiver"); try { DatagramSocket socket = new DatagramSocket(RECEIVER_PORT); out.println("- socket created and bound on port " + RECEIVER_PORT); byte[] buffer = new byte[BUFFER_SIZE]; boolean stop = false; while (stop == false) { DatagramPacket packet = new DatagramPacket(buffer, buffer.length); socket.receive(packet); String msg = new String(packet.getData(), 0, packet.getLength()); InetAddress peer = packet.getAddress(); out.println("- message " + msg.length() + "B of " + packet.getLength() + "B received from " + peer.getHostAddress() + ":" + packet.getPort() + " on port " + socket.getLocalPort()); out.println("|" + msg + "|"); if (msg.equals("stop")) { // received message "stop" to stop the receiver stop = true; } } socket.close(); out.println("- socket closed"); } catch (IOException e) { out.println("- " + e); } } }
net_udp_sender.java
Directories to net_udp_sender.java in the repository: java/cz/petrfaltus/net
package cz.petrfaltus.net; import java.io.IOException; import java.net.DatagramPacket; import java.net.DatagramSocket; import java.net.InetAddress; import java.text.DateFormat; import java.text.SimpleDateFormat; import java.util.Date; import static java.lang.System.out; public class net_udp_sender { private static final String RECEIVER_ADDRESS = "127.0.0.1"; private static final int RECEIVER_PORT = 10000; public static void main(String[] args) { out.println("UDP IPv4 datagram socket sender"); try { DatagramSocket socket = new DatagramSocket(); out.println("- socket created"); String msg; if (args.length > 0) { msg = args[0]; // message is the first parameter, for example "stop" to stop the receiver } else { Date now = new Date(); DateFormat date_format = new SimpleDateFormat("d.M.yyyy 'in' H:mm:ss"); msg = "This is Java message sent at " + date_format.format(now); } out.println("|" + msg + "|"); byte[] buffer = msg.getBytes(); InetAddress receiver_address = InetAddress.getByName(RECEIVER_ADDRESS); DatagramPacket packet = new DatagramPacket(buffer, buffer.length, receiver_address, RECEIVER_PORT); InetAddress peer = packet.getAddress(); out.println("- for " + peer.getHostAddress() + ":" + packet.getPort() + " bound on port " + socket.getLocalPort()); socket.send(packet); out.println("- message " + buffer.length + "B of " + msg.length() + "B sent to " + RECEIVER_ADDRESS + ":" + RECEIVER_PORT); socket.close(); out.println("- socket closed"); } catch (IOException e) { out.println("- " + e); } } }
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