Component that produces JSON

Yes, we can do it.

Please have a look at this article :

Link:- http://www.nateyolles.com/blog/2015/12/converting-aem-sling-resources-to-json

// Converting AEM/Sling Resources to JSON : You can easily convert an AEM Page, Sling Resource, or JCR Node to JSON using the org.apache.sling.commons.json.jcr.JsonItemWriter class. 

Also have a look at this example:

Link:- https://github.com/Adobe-Consulting-Services/acs-aem-samples/blob/master/bundle/src/main/java/com/adobe/acs/samples/servlets/impl/SampleAllMethodsServlet.java

//

     JSONObject jsonResponse = new JSONObject();
            try {
                jsonResponse.put("success", true);
                jsonResponse.put("new-world", newWorld);
                // Write the JSON to the response
                response.getWriter().write(jsonResponse.toString(2));
                // Be default, a 200 HTTP Response Status code is used
            } catch (JSONException e) {
                log.error("Could not formulate JSON response");
                // Servlet failures should always return an approriate HTTP Status code
                response.setStatus(SlingHttpServletResponse.SC_INTERNAL_SERVER_ERROR);
                // If you do not set your own HTML Response content, the OOTB HATEOS Response is used
                response.getWriter().write("ERROR");
            }
        }

I hope this would help you.

~kautuk