Refactor common code into the xxxOperations classes

   private List<JavaResource> getProjectEntities(Project project)
   {
      final List<JavaResource> entities = new ArrayList<>();
      if (project != null)
      {
         project.getFacet(JavaSourceFacet.class).visitJavaSources(new JavaResourceVisitor()
         {
            @Override
            public void visit(VisitContext context, JavaResource resource)
            {
               try
               {
                  JavaSource<?> javaSource = resource.getJavaType();
                  if (javaSource.hasAnnotation(Entity.class) || javaSource.hasAnnotation(Embeddable.class)
                           || javaSource.hasAnnotation(MappedSuperclass.class))
                  {
                     entities.add(resource);
                  }
               }
               catch (ResourceException | FileNotFoundException e)
               {
                  // ignore
               }
            }
         });
      }
      return entities;
   }