Added default prefixes

sdcf4j-core/src/main/java/de/btobastian/sdcf4j/CommandHandler.java

@@ -33,6 +33,8 @@ public abstract class CommandHandler {
     protected final List<SimpleCommand> commandList = new ArrayList<>();
     private final HashMap<String, List<String>> permissions = new HashMap<>();
 
+    protected String defaultPrefix = "";
+
     /**
      * Registers an executor.
      *
@@ -50,7 +52,7 @@ public void registerCommand(CommandExecutor executor) {
             SimpleCommand command = new SimpleCommand(annotation, method, executor);
             for (String alias : annotation.aliases()) {
                 // add command to map. It's faster to access it from the map than iterating to the whole list
-                commands.put(alias.toLowerCase(), command);
+                commands.put(defaultPrefix + alias.toLowerCase().replace(" ", ""), command);
             }
             // we need a list, too, because a HashMap is not ordered.
             commandList.add(command);
@@ -107,6 +109,29 @@ public List<SimpleCommand> getCommands() {
         return Collections.unmodifiableList(commandList);
     }
 
+    /**
+     * Sets the default command prefix.
+     * Changing the default prefix after registering a command has no effect!
+     *
+     * @param defaultPrefix The default command prefix.
+     */
+    public void setDefaultPrefix(String defaultPrefix) {
+        if (defaultPrefix == null) {
+            this.defaultPrefix = "";
+        } else {
+            this.defaultPrefix = defaultPrefix.replace(" ", "");
+        }
+    }
+
+    /**
+     * Gets the default command prefix.
+     *
+     * @return The default command prefix.
+     */
+    public String getDefaultPrefix() {
+        return defaultPrefix;
+    }
+
     /**
      * Checks if you are allowed to do something with the given permission.
      *