refactoring after code review

Author: bohdan-harniuk

src/com/magento/idea/magento2plugin/actions/generation/dialog/NewUiComponentFormDialog.java

@@ -547,7 +547,7 @@ private List<String> getAreaList() {
     }
 
     private List<String> getAclResourcesList() {
-        return GetAclResourcesListUtil.getInstance().execute(project);
+        return GetAclResourcesListUtil.execute(project);
     }
 
     @SuppressWarnings({"PMD.UnusedPrivateMethod"})

src/com/magento/idea/magento2plugin/actions/generation/generator/AclXmlGenerator.java

@@ -86,7 +86,7 @@ public PsiFile generate(final String actionName) {
             childParentRelationMap.put(resourcesTag, aclTag);
         }
 
-        final List<AclXmlData> tree = GetAclResourcesTreeUtil.getInstance().execute(
+        final List<AclXmlData> tree = GetAclResourcesTreeUtil.execute(
                 project,
                 aclXmlData.getParentResourceId()
         );

src/com/magento/idea/magento2plugin/util/magento/GetAclResourcesListUtil.java

@@ -12,18 +12,8 @@
 import java.util.List;
 import java.util.stream.Collectors;
 
-public class GetAclResourcesListUtil {
+public final class GetAclResourcesListUtil {
     private static final String TEST_MODULE_ID_PART = "Magento_TestModule";
-    private static final GetAclResourcesListUtil INSTANCE = new GetAclResourcesListUtil();
-
-    /**
-     * Get GetAclResourcesListUtil instance.
-     *
-     * @return GetAclResourcesUtil
-     */
-    public static GetAclResourcesListUtil getInstance() {
-        return INSTANCE;
-    }
 
     /**
      * Get acl resources list.
@@ -32,7 +22,7 @@ public static GetAclResourcesListUtil getInstance() {
      *
      * @return List
      */
-    public List<String> execute(final Project project) {
+    public static List<String> execute(final Project project) {
         final Collection<String> allAclResources =
                 FileBasedIndex.getInstance().getAllKeys(AclResourceIndex.KEY, project);
         return sortAclResources(filterTestModules(allAclResources));
@@ -45,7 +35,7 @@ public List<String> execute(final Project project) {
      *
      * @return List
      */
-    private List<String> filterTestModules(final Collection<String> allAclResources) {
+    private static List<String> filterTestModules(final Collection<String> allAclResources) {
         return allAclResources
                 .stream()
                 .filter(aclResource -> !aclResource.contains(TEST_MODULE_ID_PART))
@@ -59,7 +49,7 @@ private List<String> filterTestModules(final Collection<String> allAclResources)
      *
      * @return List
      */
-    private List<String> sortAclResources(final List<String> aclResources) {
+    private static List<String> sortAclResources(final List<String> aclResources) {
         return aclResources.stream().sorted().collect(Collectors.toList());
     }
 }

src/com/magento/idea/magento2plugin/util/magento/GetAclResourcesTreeUtil.java

@@ -21,24 +21,17 @@
 import java.util.LinkedList;
 import java.util.List;
 
-public class GetAclResourcesTreeUtil {
-    private static final GetAclResourcesTreeUtil INSTANCE = new GetAclResourcesTreeUtil();
-
-    /**
-     * Get GetAclResourcesTreeUtil instance.
-     *
-     * @return GetAclResourcesUtil
-     */
-    public static GetAclResourcesTreeUtil getInstance() {
-        return INSTANCE;
-    }
+public final class GetAclResourcesTreeUtil {
 
     /**
      * Get acl resources tree list for specified acl resource id.
      *
      * @return List
      */
-    public List<AclXmlData> execute(final Project project, final String targetAclResourceId) {
+    public static List<AclXmlData> execute(
+            final Project project,
+            final String targetAclResourceId
+    ) {
         final Collection<VirtualFile> virtualFiles =
                 FileBasedIndex.getInstance().getContainingFiles(
                         AclResourceIndex.KEY,
@@ -89,7 +82,7 @@ public List<AclXmlData> execute(final Project project, final String targetAclRes
      *
      * @return List
      */
-    private List<XmlTag> addAclXmlDataRecursively(
+    private static List<XmlTag> addAclXmlDataRecursively(
             final String targetAclResourceId,
             final XmlTag parentTag,
             List<XmlTag> resourceTagsList//NOPMD