source: src/main/java/geniusweb/partiesserver/Info.java@ 24

package geniusweb.partiesserver;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.fasterxml.jackson.databind.ObjectMapper;

import geniusweb.partiesserver.repository.RunningPartiesRepo;
import geniusweb.serverobjects.ServerInfo;

/**
 * Servlet implementation to get general info from the server.
 */
public class Info extends HttpServlet {

        private final static RunningPartiesRepo repo = RunningPartiesRepo
                        .instance();
        private final static ObjectMapper jackson = new ObjectMapper();

        /**
         * see
         * {@link HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)}.
         * Returns to the http caller
         * <ul>
         * <li>URL with websocket address to contact the now running agent.
         * <li>SC_NOT_FOUND (404) if attempt is made to access non-running party.
         * <li>SC_SERVICE_UNAVAILABLE (503) if there are no free slots to run the
         * party.
         * <li>SC_EXPECTATION_FAILED (417) if something else goes wrong during
         * instantiating the party (then see logs for more details)
         * </ul>
         */
        @Override
        protected void doGet(HttpServletRequest request,
                        HttpServletResponse response) throws ServletException, IOException {
                response.getWriter().append(jackson.writeValueAsString(
                                new ServerInfo(repo.availableSlots(), repo.maximumSlots())));
        }
}