src/de/steamwar/bungeecore/commands/BanCommand.java

@@ -42,7 +42,7 @@ public class BanCommand extends BasicCommand {
             return;
         }
 
-        SteamwarUser target = user(sender, args[0]);
+        SteamwarUser target = unsafeUser(sender, args[0]);
         if(target == null)
             return;
 

src/de/steamwar/bungeecore/commands/BasicCommand.java

@@ -53,10 +53,17 @@ abstract class BasicCommand extends Command implements TabExecutor {
         return new ArrayList<>();
     }
 
-    protected SteamwarUser user(CommandSender sender, String arg){
+    protected SteamwarUser existingUser(CommandSender sender, String arg){
         SteamwarUser target = SteamwarUser.get(arg);
         if(target == null)
             Message.send("UNKNOWN_PLAYER", sender);
         return target;
     }
+
+    protected SteamwarUser unsafeUser(CommandSender sender, String arg){
+        SteamwarUser target = SteamwarUser.getOrCreateOfflinePlayer(arg);
+        if(target == null)
+            Message.send("UNKNOWN_PLAYER", sender);
+        return target;
+    }
 }

src/de/steamwar/bungeecore/commands/MuteCommand.java

@@ -38,7 +38,7 @@ public class MuteCommand extends BasicCommand {
             return;
         }
 
-        SteamwarUser target = user(sender, args[0]);
+        SteamwarUser target = unsafeUser(sender, args[0]);
         if(target == null)
             return;
 

src/de/steamwar/bungeecore/commands/UnbanCommand.java

@@ -39,7 +39,7 @@ public class UnbanCommand extends BasicCommand {
             return;
         }
 
-        SteamwarUser target = user(sender, args[0]);
+        SteamwarUser target = existingUser(sender, args[0]);
         if(target == null)
             return;
 

src/de/steamwar/bungeecore/sql/SteamwarUser.java

@@ -19,10 +19,15 @@
 
 package de.steamwar.bungeecore.sql;
 
+import com.google.gson.JsonParser;
 import de.steamwar.bungeecore.BungeeCore;
 import de.steamwar.bungeecore.Message;
 import de.steamwar.bungeecore.commands.WebregisterCommand;
 import de.steamwar.bungeecore.listeners.ConnectionListener;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Scanner;
 import net.md_5.bungee.api.ProxyServer;
 import net.md_5.bungee.api.chat.TextComponent;
 import net.md_5.bungee.api.connection.PendingConnection;
@@ -38,6 +43,7 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.UUID;
 
+
 public class SteamwarUser {
     private final int id;
     private final UUID uuid;
@@ -51,6 +57,8 @@ public class SteamwarUser {
     private static final Map<UUID, SteamwarUser> usersByUUID = new HashMap<>();
     private static final Map<Integer, SteamwarUser> usersById = new HashMap<>();
     private static final InetAddress LIXFEL_DE;
+    private static final String API_URL = "https://api.mojang.com/users/profiles/minecraft/";
+    private static final JsonParser jsonParser = new JsonParser();
 
     static {
         try {
@@ -85,8 +93,7 @@ public class SteamwarUser {
                 user.userName = userName;
             }
         }else{
-            SQL.update("INSERT INTO UserData (UUID, UserName, UserGroup) VALUES (?, ?, 'Member')", connection.getUniqueId().toString(), connection.getName());
-            user = dbInit(SQL.select("SELECT * FROM UserData WHERE UUID = ?", connection.getUniqueId().toString()));
+            user = SteamwarUser.createUserInDatabase(connection.getUniqueId(), connection.getName());
             if(user == null)
                 throw new SecurityException("user == null");
             ConnectionListener.newPlayer(user.uuid);
@@ -97,6 +104,25 @@ public class SteamwarUser {
         return user;
     }
 
+    public static SteamwarUser getOrCreateOfflinePlayer(String name){
+        SteamwarUser user = SteamwarUser.get(name);
+        if (user != null) {
+            return user;
+        }
+
+        UUID uuid = SteamwarUser.loadUUID(name);
+        if (uuid == null) {
+            return null;
+        }
+
+        return SteamwarUser.createUserInDatabase(uuid, name);
+    }
+
+    private static SteamwarUser createUserInDatabase(UUID uuid, String name) {
+        SQL.update("INSERT INTO UserData (UUID, UserName, UserGroup) VALUES (?, ?, 'Member')", uuid.toString(), name);
+        return dbInit(SQL.select("SELECT * FROM UserData WHERE UUID = ?", uuid.toString()));
+    }
+
     public static SteamwarUser get(String userName){
         userName = userName.toLowerCase();
         if(usersByName.containsKey(userName))
@@ -126,6 +152,22 @@ public class SteamwarUser {
         usersByUUID.clear();
     }
 
+    public static UUID loadUUID(String playerName) {
+        try {
+            final URL url = new URL(API_URL + playerName);
+            return getUniqueIdFromString(jsonParser.parse(new Scanner(url.openConnection().getInputStream()).nextLine()).getAsJsonObject().get("id").getAsString());
+        } catch (MalformedURLException e) {
+            e.printStackTrace();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        return null;
+    }
+
+    private static UUID getUniqueIdFromString(String uuid) {
+        return UUID.fromString(uuid.replaceFirst("(\\w{8})(\\w{4})(\\w{4})(\\w{4})(\\w{12})", "$1-$2-$3-$4-$5"));
+    }
+
     public void setTeam(int team){
         this.team = team;
         SQL.update("Update UserData SET Team = ? WHERE id = ?", team, id);