Update AbstractSWCommand.ErrorMessage

src/de/steamwar/command/AbstractSWCommand.java

@@ -381,5 +381,10 @@ public abstract class AbstractSWCommand<T> {
          * Error message to be displayed when the parameter is invalid.
          */
         String value();
+
+        /**
+         * This is the short form for 'allowEmptyArrays'.
+         */
+        boolean allowEAs() default true;
     }
 }

src/de/steamwar/command/SWCommandUtils.java

@@ -23,6 +23,7 @@ import lombok.Getter;
 import lombok.experimental.UtilityClass;
 
 import java.lang.annotation.Annotation;
+import java.lang.reflect.Array;
 import java.lang.reflect.Method;
 import java.lang.reflect.Parameter;
 import java.util.*;
@@ -187,8 +188,12 @@ public class SWCommandUtils {
 
         AbstractSWCommand.ErrorMessage errorMessage = parameter.getAnnotation(AbstractSWCommand.ErrorMessage.class);
         if (errorMessage != null) {
-            return (AbstractValidator<T, String>) (sender, value, messageSender) -> {
-                if (value == null) messageSender.send(errorMessage.value(), new Object[0]);
+            return (AbstractValidator<T, Object>) (sender, value, messageSender) -> {
+                if (value == null) messageSender.send(errorMessage.value());
+                if (!errorMessage.allowEAs() && value != null && value.getClass().isArray() && Array.getLength(value) == 0) {
+                    messageSender.send(errorMessage.value());
+                    return false;
+                }
                 return value != null;
             };
         }