Solved time praktikum

VAR-UDP/src/var/sockets/udp/time/TimeClient.java

@@ -1,8 +1,35 @@
 package var.sockets.udp.time;
 
-public class TimeClient {
+import java.net.*;
 
-  public static void main(String[] args) {
-    // TODO Auto-generated method stub
-  }
+public class TimeClient {
+    private static final String HOST = "localhost";
+    private static final int PORT = 4711;
+    private static final int BUFSIZE = 512;
+    private static final int TIMEOUT = 2000;
+
+    public static void main(String[] args) {
+        System.out.println("Sending empty Datagram...");
+        byte[] data = {};
+
+        try (DatagramSocket socket = new DatagramSocket()) {
+            socket.setSoTimeout(TIMEOUT);
+
+            InetAddress iaddr = InetAddress.getByName(HOST);
+            DatagramPacket packetOut = new DatagramPacket(data, 0, iaddr, PORT);
+            socket.send(packetOut);
+
+            DatagramPacket packetIn = new DatagramPacket(new byte[BUFSIZE], BUFSIZE);
+            socket.receive(packetIn);
+            String received = new String(packetIn.getData(), 0, packetIn.getLength());
+            System.out.println("Received: " + received);
+
+        }
+        catch (SocketTimeoutException e) {
+            System.err.println("Timeout: " + e.getMessage());
+        }
+        catch (Exception e) {
+            System.err.println(e);
+        }
+    }
 }

VAR-UDP/src/var/sockets/udp/time/TimeServer.java

@@ -1,8 +1,40 @@
 package var.sockets.udp.time;
 
-public class TimeServer {
+import java.io.IOException;
+import java.net.DatagramPacket;
+import java.net.DatagramSocket;
+import java.util.Date;
 
-  public static void main(String[] args) {
-    // TODO Auto-generated method stub
-  }
+public class TimeServer {
+    private static  final int PORT = 4711;
+    private static final int BUFSIZE = 512;
+
+    public static void main(String[] args) {
+        try (DatagramSocket socket = new DatagramSocket(PORT)) {
+            DatagramPacket packetIn = new DatagramPacket(new byte[BUFSIZE], BUFSIZE);
+            DatagramPacket packetOut = new DatagramPacket(new byte[BUFSIZE], BUFSIZE);
+
+            System.out.println("Time Server gestarted ...");
+
+            while (true) {
+                System.out.println("\nListening: ");
+                socket.receive(packetIn);
+                System.out.println(
+                        "Received: " + packetIn.getLength() + " bytes: " + new String(packetIn.getData()));
+
+                packetOut.setSocketAddress(packetIn.getSocketAddress());
+                Date currentStamp = new Date();
+                String currentStampString = currentStamp.toString();
+                byte[] outData = currentStampString.getBytes();
+
+                packetOut.setData(outData);
+                packetOut.setLength(outData.length);
+
+                socket.send(packetOut);
+            }
+        }
+        catch (IOException e) {
+            System.err.println(e);
+        }
+    }
 }