As a best practice to enforce re-usability, Maybe you can extract the business logic from the servlet into an OSGI service, so that all of your OSGI components can be using the same service. 

@SivaReddy0128,you are absolutely right. When I analyzed the out of the box content fragment component, it does not have any options to display all fields for a given content fragment... dam/cfm/components/contentfragment.  My suggestion is to create your own.

Using the sightly features, you can use the data-sly-test.A standard practice is to use ternary conditions in Sightly HTL. While using Sightly, I would like to highlight that you can use Slightly Global objects for rapid development. AEM Global Objects for Backend and Front-end Sightly (HTL) Develop...

Hello,AEM uses Apache Sling as the REST web application framework.

You can add, addModelsForPackage, as this is another common null returned from adapt.aemContext.addModelsForPackage("com.sourcedcode.core.models.utils"); 

what does the error.log say?

This is a fairly clean approach. Nice one!

A possible scenario is that you don't have ACL, edit permission on the path of the page resourced. Checkout http://localhost:4502/useradmin, and ensure that you have edit permission for that given user. 

My input is, you can use a Experience Fragments strategy to add reusable-structured-data in your AEM pages. 

There are many ways to do this, but here's what I would do.Pre-requirement is for you to actually be familiar with AngularJS vs Angular. And understanding how to migrate AngularJS components to Angular. I searched on youtube "migrate AngularJS components to Angular", (1) JavaScript Marathon: Upgrade...