groovy mode has been added to be used for gradle

lib/extensions/java.el

@@ -9,6 +9,9 @@
 ;; Dependencies ----------------------------------
 
 (depends-on 'gradle-mode)
+(depends-on 'flycheck-gradle)
+
+(depends-on 'groovy-mode)
 
 (with-ability lsp-java
               (depends-on 'lsp-java))

lib/extensions/java/init.el

@@ -6,6 +6,9 @@
 (defun extensions/java-initialize ()
   "Initialize the common Lisp extension."
 
+  (add-to-list 'auto-mode-alist
+               '("\\.gradle\\'" . groovy-mode))
+
   (require 'gradle-mode)
   (add-hook 'java-mode-hook
             '(lambda()