I need to develop the component which contain drop down and that dropdown i need to consume service from
What are all methodology to archive this.
This service returns a simple json object.
As @gauravb10066713 mentions you can write a custom AEM service that is able to use Java to consume a 3rd party RESTFul web service. In our little example - we consume a Google RESTFul service and displays the result in an AEM component.