Implemented starting everything from NightTrainToBudapest class.

src/main/java/ch/unibas/dmi/dbis/cs108/NightTrainToBudapest.java

@@ -0,0 +1,39 @@
+package ch.unibas.dmi.dbis.cs108;
+
+import ch.unibas.dmi.dbis.cs108.multiplayer.client.Client;
+import ch.unibas.dmi.dbis.cs108.multiplayer.server.Server;
+import java.net.InetAddress;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.apache.logging.log4j.core.tools.picocli.CommandLine.Help.IParameterRenderer;
+
+public class NightTrainToBudapest {
+
+  public static void main(String[] args){
+    try{
+      String clientOrServer = args[0];
+      if (clientOrServer.equalsIgnoreCase("client")) {
+        String addrString = args[1].substring(0,args[1].indexOf(":"));
+        InetAddress addr = InetAddress.getByName(addrString);
+        int port = Integer.parseInt(args[1].substring(args[1].indexOf(":") + 1));
+        String username = null;
+        if (args.length > 2) { //if the client provided a username
+          //StringBuilder usernamebuilder = new StringBuilder(); todo: support username with spaces.
+          username = args[2];
+        }
+        Client.main(addr, port, username);
+      } else if (clientOrServer.equalsIgnoreCase("server")) {
+        int port = Integer.parseInt(args[1]);
+        Server.main(port);
+      } else {
+        System.out.println("invalid arguments!");
+      }
+
+    } catch (Exception e) {
+      System.out.println("Please give more arguments.");
+      System.out.println("Syntax:");
+      System.out.println("client <hostadress>:<port> [<username>] | server <port>");
+      e.printStackTrace();
+    }
+  }
+}