ex.java

@GET
    @Path("/")
    @Produces(MediaType.APPLICATION_JSON)
    @ApiOperation(value = "This method returns a list of activities",
            notes = "Default the latest ten activities will be returned")
    @ApiResponses(value = {
            @ApiResponse(code = HttpURLConnection.HTTP_OK, message = "Returns a list of activities"),
            @ApiResponse(code = HttpURLConnection.HTTP_NOT_FOUND, message = "Not found"),
            @ApiResponse(code = HttpURLConnection.HTTP_INTERNAL_ERROR, message = "Internal server problems")
    })
    //TODO add filter
    public HttpResponse getActivities(
            @ApiParam(value = "Page number", required = false) @DefaultValue("0") @QueryParam("page") int page,
            @ApiParam(value = "Elements of components by page", required = false) @DefaultValue("10") @QueryParam("per_page") int perPage,
            @ApiParam(value = "User access token", required = false) @DefaultValue("") @QueryParam("access_token") String accessToken) {
        List<Activity> activities = new ArrayList<Activity>();
        List<ActivityEx> activitiesEx = new ArrayList<ActivityEx>();
        DALFacade dalFacade = null;

        PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager();
        cm.setMaxTotal(20);
        CloseableHttpClient httpclient = HttpClients.custom()
                .setConnectionManager(cm)
                .build();
        try {
            dalFacade = createConnection();
            Gson gson = new Gson();
            Pageable pageInfo = new PageInfo(page, perPage);

            activities = dalFacade.findActivities(pageInfo);

            ExecutorService executor = Executors.newCachedThreadPool();
            HttpGet httpget;
            Future<String> future;
            JsonParser parser = new JsonParser();
            for (Activity activity : activities) {
                ActivityEx activityEx = ActivityEx.getBuilderEx().activity(activity).build();
                //TODO check if this runs paralel or if I need to create Threads
                try {
                    if (!activity.getDataUrl().isEmpty()) {
                        URIBuilder uriBuilder = new URIBuilder(activity.getDataUrl());
                        if (!accessToken.isEmpty()) {
                            uriBuilder.setParameter("access_token", accessToken);
                        }
                        URI uri = uriBuilder.build();
                        httpget = new HttpGet(uri);
                        future = executor.submit(new HttpRequestCallable(httpclient, httpget));
                        activityEx.setData(parser.parse(future.get()));
                    }
                    if (!activity.getUserUrl().isEmpty()) {
                        URIBuilder uriBuilder = new URIBuilder(activity.getUserUrl());
                        if (!accessToken.isEmpty()) {
                            uriBuilder.setParameter("access_token", accessToken);
                        }
                        URI uri = uriBuilder.build();
                        httpget = new HttpGet(uri);
                        future = executor.submit(new HttpRequestCallable(httpclient, httpget));
                        activityEx.setUser(parser.parse(future.get()));
                    }
                    activitiesEx.add(activityEx);
                } catch (Exception ex) {
                    if (ex instanceof ActivityTrackerException &&
                            ((ActivityTrackerException) ex).getErrorCode() == ErrorCode.AUTHORIZATION) {

                    } else {
                        throw ex;
                    }
                }
            }
            executor.shutdown();
            return new HttpResponse(gson.toJson(activitiesEx), HttpURLConnection.HTTP_OK);
        } catch (Exception ex) {
            ActivityTrackerException atException = ExceptionHandler.getInstance().convert(ex, ExceptionLocation.ACTIVITIESERVICE, ErrorCode.UNKNOWN, "");
            return new HttpResponse(ExceptionHandler.getInstance().toJSON(atException), HttpURLConnection.HTTP_INTERNAL_ERROR);
        } finally {
            closeConnection(dalFacade);
        }
    }