@Override
  public ObjectNode execute(final HttpServletRequest request) throws Exception {

    // get cluster object
    Cluster cluster = repository.getCluster();

    // json object to be sent as response
    ObjectNode responseJSON = mapper.createObjectNode();

    JsonNode requestDataJSON = mapper.readTree(request.getParameter("pulseData"));
    int pageNumber = 1; // Default
    String strPageNumber = requestDataJSON.get("SystemAlerts").get("pageNumber").textValue();
    if (StringUtils.isNotBlank(strPageNumber)) {
      try {
        pageNumber = Integer.parseInt(strPageNumber);
      } catch (NumberFormatException ignored) {
      }
    }

    // cluster's Members
    responseJSON.set("systemAlerts", getAlertsJson(cluster, pageNumber));
    responseJSON.put("pageNumber", cluster.getNotificationPageNumber());
    responseJSON.put("connectedFlag", cluster.isConnectedFlag());
    responseJSON.put("connectedErrorMsg", cluster.getConnectionErrorMsg());

    // Send json response
    return responseJSON;
  }
Class SystemAlertsService

This class contains implementations of getting system's alerts details (like errors, warnings and
severe errors).

@since GemFire version 7.5
geode-pulse/src/main/java/org/apache/geode/tools/pulse/internal/service/SystemAlertsService.java