REST API + Java Multithreaded

I managed to build a small REST API using eclipse. The following code works:

@Path("Info")
public class Rest {

@POST
@Path("/stats/{j}") 
@Produces("application/json")
public Response Status(@PathParam("j") String j) throws JSONException{
  JSONObject jsonObject = new JSONObject();
   String status = j;
   .
   .
 return Response.status(200).entity(result).build();
}
}

Could you advise me on how make this a multithreaded? I have an idea of what is multithreaded but I need some input on how to go about creating this code as multithreaded. was thinking of creating another class that implements Runnable:

class Demo implements Runnable {
  .
  .

}

Then, in my function Status(@PathParam("j") String j), I create an object of class Demo, For example:

public Response Status(@PathParam("j") String j) throws JSONException{
    Demo newThread = new Demo();
    JSONObject jsonObject = new JSONObject();
   String status = j;
   .
   .
 return Response.status(200).entity(result).build();
}
}

Thank you in advance!