diff --git a/Core/src/main/java/fr/pandacube/lib/core/util/OfflineUUID.java b/Core/src/main/java/fr/pandacube/lib/core/util/OfflineUUID.java
index fa94f0d..91852da 100644
--- a/Core/src/main/java/fr/pandacube/lib/core/util/OfflineUUID.java
+++ b/Core/src/main/java/fr/pandacube/lib/core/util/OfflineUUID.java
@@ -1,28 +1,45 @@
 package fr.pandacube.lib.core.util;
 
 import java.nio.charset.Charset;
+import java.util.Objects;
+import java.util.Scanner;
 import java.util.UUID;
 
 public class OfflineUUID {
-	public static void main(String[] args) {
-		for (String arg : args)
-			System.out.println("" + arg + ":" + getFromNickName(arg));
-		if (args.length == 0)
-			throw new IllegalArgumentException("no argument given. Please give at least one argument.");
-	}
 
 	public static UUID getFromNickName(String nickname) {
-		String str = "OfflinePlayer:" + nickname;
-		byte[] from_str = str.getBytes(Charset.forName("UTF-8"));
+		byte[] from_str = ("OfflinePlayer:" + nickname).getBytes(Charset.forName("UTF-8"));
 		return UUID.nameUUIDFromBytes(from_str);
 	}
 
 	public static UUID[] getFromNickNames(String[] nicknames) {
-		if (nicknames == null) throw new NullPointerException();
+		Objects.requireNonNull(nicknames);
 
 		UUID[] uuids = new UUID[nicknames.length];
 		for (int i = 0; i < nicknames.length; i++)
 			uuids[i] = getFromNickName(nicknames[i]);
 		return uuids;
 	}
+	
+	
+	
+	
+	
+	public static void main(String[] args) {
+		if (args.length == 0) {
+			try (Scanner s = new Scanner(System.in)) {
+				for(;;) {
+					System.out.print("Please input a player name: ");
+					if (!s.hasNext())
+						break;
+					String line = s.nextLine();
+					System.out.println(getFromNickName(line));
+				}
+			}
+		}
+		else {
+			for (String arg : args)
+				System.out.println("" + arg + ":" + getFromNickName(arg));
+		}
+	}
 }