Closest facility (static)

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Sample viewer app

Find routes from several locations to the respective closest facility.

Image of find closest facility static

Use case

Quickly and accurately determining the most efficient route between a location and a facility is a frequently encountered task. For example, a city's fire department may need to know which fire stations in the vicinity offer the quickest routes to multiple fires. Solving for the closest fire station to the fire's location using an impedance of "travel time" would provide this information.

How to use the sample

Click the 'Solve Routes' button to solve and display the route from each incident (fire) to the nearest facility (fire station).

How it works

Create a ClosestFacilityTask using a URL from an online service.
Get the default set of ClosestFacilityParameters from the task: closestFacilityTask.createDefaultParametersAsync().get().
Build a list of all Facilitys and Incidents:

Create a FeatureTable using ServiceFeatureTable(Uri).
Query the FeatureTable for all Features using queryFeaturesAsync(queryParameters).
Iterate over the result and add each Feature to the List, instantiating the feature as a Facility or Incident.

Add a list of all facilities to the task parameters: closestFacilityParameters.setFacilities(facilitiesList).
Add a list of all incidents to the task parameters: closestFacilityParameters.setIncidents(incidentsList).
Get ClosestFacilityResult by solving the task with the provided parameters: closestFacilityTask.solveClosestFacilityAsync(closestFacilityParameters).
Find the closest facility for each incident by iterating over the list of Incidents.
Display the route as a Graphic using the closestFacilityRoute.getRouteGeometry().

Relevant API

ClosestFacilityParameters
ClosestFacilityResult
ClosestFacilityRoute
ClosestFacilityTask
Facility
Graphic
GraphicsOverlay
Incident

Sample Code

ClosestFacilityStaticSample.java
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/*
 * Copyright 2019 Esri.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.esri.samples.closest_facility_static;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.concurrent.ExecutionException;

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;
import javafx.scene.control.ProgressIndicator;
import javafx.scene.image.Image;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

import com.esri.arcgisruntime.ArcGISRuntimeEnvironment;
import com.esri.arcgisruntime.concurrent.ListenableFuture;
import com.esri.arcgisruntime.data.Feature;
import com.esri.arcgisruntime.data.FeatureQueryResult;
import com.esri.arcgisruntime.data.FeatureTable;
import com.esri.arcgisruntime.data.QueryParameters;
import com.esri.arcgisruntime.data.ServiceFeatureTable;
import com.esri.arcgisruntime.geometry.Envelope;
import com.esri.arcgisruntime.geometry.GeometryEngine;
import com.esri.arcgisruntime.geometry.Point;
import com.esri.arcgisruntime.layers.FeatureLayer;
import com.esri.arcgisruntime.loadable.LoadStatus;
import com.esri.arcgisruntime.mapping.ArcGISMap;
import com.esri.arcgisruntime.mapping.BasemapStyle;
import com.esri.arcgisruntime.mapping.view.Graphic;
import com.esri.arcgisruntime.mapping.view.GraphicsOverlay;
import com.esri.arcgisruntime.mapping.view.MapView;
import com.esri.arcgisruntime.symbology.PictureMarkerSymbol;
import com.esri.arcgisruntime.symbology.SimpleLineSymbol;
import com.esri.arcgisruntime.symbology.SimpleRenderer;
import com.esri.arcgisruntime.tasks.networkanalysis.ClosestFacilityParameters;
import com.esri.arcgisruntime.tasks.networkanalysis.ClosestFacilityResult;
import com.esri.arcgisruntime.tasks.networkanalysis.ClosestFacilityRoute;
import com.esri.arcgisruntime.tasks.networkanalysis.ClosestFacilityTask;
import com.esri.arcgisruntime.tasks.networkanalysis.Facility;
import com.esri.arcgisruntime.tasks.networkanalysis.Incident;

public class ClosestFacilityStaticSample extends Application {

  private ClosestFacilityTask closestFacilityTask; // keep loadables in scope to avoid garbage collection
  private MapView mapView;

  @Override
  public void start(Stage stage) throws Exception {

    try {
      // create stack pane and application scene
      StackPane stackPane = new StackPane();
      Scene scene = new Scene(stackPane);

      // set title, size, and add scene to stage
      stage.setTitle("Closest Facility (Static) Sample");
      stage.setWidth(800);
      stage.setHeight(700);
      stage.setScene(scene);
      stage.show();

      // authentication with an API key or named user is required to access basemaps and other location services
      String yourAPIKey = System.getProperty("apiKey");
      ArcGISRuntimeEnvironment.setApiKey(yourAPIKey);

      // create buttons
      Button solveRoutesButton = new Button("Solve Routes");
      solveRoutesButton.setMaxWidth(150);
      solveRoutesButton.setDisable(true);

      // create a progress indicator
      ProgressIndicator progressIndicator = new ProgressIndicator();
      progressIndicator.setVisible(true);

      // create a map with the streets relief basemap style
      ArcGISMap map = new ArcGISMap(BasemapStyle.ARCGIS_STREETS_RELIEF);

      // create a map view and set the map to it
      mapView = new MapView();
      mapView.setMap(map);

      // create a graphics overlay and add it to the map
      GraphicsOverlay graphicsOverlay = new GraphicsOverlay();
      mapView.getGraphicsOverlays().add(graphicsOverlay);

      // create Symbols for displaying facilities
      PictureMarkerSymbol facilitySymbol = new PictureMarkerSymbol(new Image("https://static.arcgis.com/images/Symbols/SafetyHealth/FireStation.png", 30, 30, true, false));
      PictureMarkerSymbol incidentSymbol = new PictureMarkerSymbol(new Image("https://static.arcgis.com/images/Symbols/SafetyHealth/esriCrimeMarker_56_Gradient.png", 30, 30, true, false));

      // create a line symbol to mark the route
      SimpleLineSymbol simpleLineSymbol = new SimpleLineSymbol(SimpleLineSymbol.Style.SOLID, 0x4D0000FF, 5.0f);

      // create a closest facility task from a network analysis service
      closestFacilityTask = new ClosestFacilityTask("https://sampleserver6.arcgisonline.com/arcgis/rest/services/NetworkAnalysis/SanDiego/NAServer/ClosestFacility");

      // create a table for facilities using the feature service
      FeatureTable facilitiesFeatureTable = new ServiceFeatureTable("https://services2.arcgis.com/ZQgQTuoyBrtmoGdP/ArcGIS/rest/services/San_Diego_Facilities/FeatureServer/0");
      // create a feature layer from the table, apply facilities icon
      FeatureLayer facilitiesFeatureLayer = new FeatureLayer(facilitiesFeatureTable);
      facilitiesFeatureLayer.setRenderer(new SimpleRenderer(facilitySymbol));

      // create a table for incidents using the feature service
      FeatureTable incidentsFeatureTable = new ServiceFeatureTable("https://services2.arcgis.com/ZQgQTuoyBrtmoGdP/ArcGIS/rest/services/San_Diego_Incidents/FeatureServer/0");
      // create a feature layer from the table, apply incident icon
      FeatureLayer incidentsFeatureLayer = new FeatureLayer(incidentsFeatureTable);
      incidentsFeatureLayer.setRenderer(new SimpleRenderer(incidentSymbol));

      // add the layers to the map
      map.getOperationalLayers().addAll(Arrays.asList(facilitiesFeatureLayer, incidentsFeatureLayer));

      // create the list to store the facilities
      ArrayList<Facility> facilities = new ArrayList<>();

      // create the list to store the incidents
      ArrayList<Incident> incidents = new ArrayList<>();

      // wait for the feature layers to load to retrieve the facilities and incidents
      facilitiesFeatureLayer.addDoneLoadingListener(() -> incidentsFeatureLayer.addDoneLoadingListener(() -> {
        if (facilitiesFeatureLayer.getLoadStatus() == LoadStatus.LOADED && incidentsFeatureLayer.getLoadStatus() == LoadStatus.LOADED) {

          // hide the progress indicator
          progressIndicator.setVisible(false);

          // zoom to the extent of the combined feature layers
          Envelope fullFeatureLayerExtent = GeometryEngine.combineExtents(facilitiesFeatureLayer.getFullExtent(), incidentsFeatureLayer.getFullExtent());
          mapView.setViewpointGeometryAsync(fullFeatureLayerExtent, 90);

          // create query parameters to select all features
          QueryParameters queryParameters = new QueryParameters();
          queryParameters.setWhereClause("1=1");

          // retrieve a list of all facilities
          ListenableFuture<FeatureQueryResult> result = facilitiesFeatureTable.queryFeaturesAsync(queryParameters);
          result.addDoneListener(() -> {
            try {
              FeatureQueryResult facilitiesResult = result.get();

              // add the found facilities to the list
              for (Feature facilityFeature : facilitiesResult) {
                // since we know our feature layer only contains point features, we can cast them as Point in order to create a Facility
                facilities.add(new Facility((Point) facilityFeature.getGeometry()));
              }

            } catch (InterruptedException | ExecutionException e) {
              new Alert(Alert.AlertType.ERROR, "Error retrieving list of facilities.").show();
            }
          });

          // retrieve a list of all incidents
          ListenableFuture<FeatureQueryResult> incidentsQueryResult = incidentsFeatureTable.queryFeaturesAsync(queryParameters);
          incidentsQueryResult.addDoneListener(() -> {
            try {
              FeatureQueryResult incidentsResult = incidentsQueryResult.get();

              // add the found incidents to the list
              for (Feature incidentFeature : incidentsResult) {
                // since we know our feature layer only contains point features, we can cast them as Point in order to create an Incident
                incidents.add(new Incident((Point) incidentFeature.getGeometry()));
              }

            } catch (InterruptedException | ExecutionException e) {
              new Alert(Alert.AlertType.ERROR, "Error retrieving list of incidents.").show();
            }
          });

          // enable the 'solve routes' button
          solveRoutesButton.setDisable(false);

          // resolve button press
          solveRoutesButton.setOnAction(e -> {

            // disable the 'solve routes' button and show the progress indicator
            solveRoutesButton.setDisable(true);
            progressIndicator.setVisible(true);

            // start the routing task
            closestFacilityTask.loadAsync();
            closestFacilityTask.addDoneLoadingListener(() -> {
              if (closestFacilityTask.getLoadStatus() == LoadStatus.LOADED) {
                try {
                  // create default parameters for the task and add facilities and incidents to parameters
                  ClosestFacilityParameters closestFacilityParameters = closestFacilityTask.createDefaultParametersAsync().get();
                  closestFacilityParameters.setFacilities(facilities);
                  closestFacilityParameters.setIncidents(incidents);

                  // solve closest facilities
                  try {
                    // use the task to solve for the closest facility
                    ListenableFuture<ClosestFacilityResult> closestFacilityTaskResult = closestFacilityTask.solveClosestFacilityAsync(closestFacilityParameters);
                    closestFacilityTaskResult.addDoneListener(() -> {
                      try {
                        ClosestFacilityResult closestFacilityResult = closestFacilityTaskResult.get();

                        // find the closest facility for each incident
                        for (int incidentIndex = 0; incidentIndex < incidents.size(); incidentIndex++) {

                          // get the index of the closest facility to incident
                          Integer closestFacilityIndex = closestFacilityResult.getRankedFacilityIndexes(incidentIndex).get(0);

                          // get the route to the closest facility
                          ClosestFacilityRoute closestFacilityRoute = closestFacilityResult.getRoute(closestFacilityIndex, incidentIndex);

                          // display the route on the graphics overlay
                          graphicsOverlay.getGraphics().add(new Graphic(closestFacilityRoute.getRouteGeometry(), simpleLineSymbol));

                          // hide the progress indicator
                          progressIndicator.setVisible(false);
                        }

                      } catch (ExecutionException | InterruptedException ex) {
                        new Alert(Alert.AlertType.ERROR, "Error getting the closest facility task result.").show();
                      }
                    });

                  } catch (Exception ex) {
                    new Alert(Alert.AlertType.ERROR, "Error solving the closest facility task.").show();
                  }

                } catch (InterruptedException | ExecutionException ex) {
                  new Alert(Alert.AlertType.ERROR, "Error getting default route parameters.").show();
                }

              } else {
                new Alert(Alert.AlertType.ERROR, "Error loading route task.").show();
              }
            });
          });
        }
      })
      );

      // add the map view, control panel and progress indicator to the stack pane
      stackPane.getChildren().addAll(mapView, solveRoutesButton, progressIndicator);
      StackPane.setAlignment(solveRoutesButton, Pos.TOP_LEFT);
      StackPane.setMargin(solveRoutesButton, new Insets(10, 0, 0, 10));

    } catch (Exception e) {
      e.printStackTrace();
    }
  }

  /**
   * Stops and releases all resources used in application.
   */
  @Override
  public void stop() {

    if (mapView != null) {
      mapView.dispose();
    }
  }

  /**
   * Opens and runs application.
   *
   * @param args arguments passed to this application
   */
  public static void main(String[] args) {

    Application.launch(args);
  }
}