Jsonp is not in expected format

[joseph prabhu]

The code i have written to get the data and to format in jsonp format. is below

private static ObjectMapper mapper = new ObjectMapper();
response.setContentType("application/json; charset=" + "UTF-8");
		response.setCharacterEncoding("UTF-8");
		Writer writer = new OutputStreamWriter(response.getOutputStream(), "UTF-8");

String q = request.getParameter("q");
		String callback = request.getParameter("callback");
SearchAutoCompleteResponse resp = service.getAutoComplete(req);
			
			if (resp != null)
				suggestions = resp.getSuggestions();
			
			if (callback != null) {
				 json=new JSONPObject(callback, suggestions);
				System.out.println(json.getValue() +" " +json.getFunction() );
				System.out.println(mapper);
			      mapper.writeValue(writer, json);
request.setAttribute("suggestions", json);

The expected output in jsp is

callback({"q":["A","B"]})

But my output is

callback(["A","B"]).

Please help how to format is