ArcGIS Runtime SDK for Java

Generate Offline Map

Demonstrates how to take a web map offline.

How it works

To take a web map offline:

  1. Create an ArcGISMap with a portal item pointing to the web map.
  2. Create GenerateOfflineMapParameters specifying the download area geometry, min scale, and max scale.
  3. Create an OfflineMapTask with the map.
  4. Create the offline map job with task.generateOfflineMap(params, downloadDirectoryPath) and start it with job.start().
  5. When the job is done, get the offline map with job.getResult().getOfflineMap().

Code

/*
 * Copyright 2018 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.map.generate_offline_map;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;

import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Point2D;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;
import javafx.scene.control.ProgressBar;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

import com.esri.arcgisruntime.concurrent.Job;
import com.esri.arcgisruntime.geometry.Envelope;
import com.esri.arcgisruntime.geometry.Point;
import com.esri.arcgisruntime.loadable.LoadStatus;
import com.esri.arcgisruntime.mapping.ArcGISMap;
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.portal.Portal;
import com.esri.arcgisruntime.portal.PortalItem;
import com.esri.arcgisruntime.security.AuthenticationManager;
import com.esri.arcgisruntime.security.DefaultAuthenticationChallengeHandler;
import com.esri.arcgisruntime.symbology.SimpleLineSymbol;
import com.esri.arcgisruntime.tasks.offlinemap.GenerateOfflineMapJob;
import com.esri.arcgisruntime.tasks.offlinemap.GenerateOfflineMapParameters;
import com.esri.arcgisruntime.tasks.offlinemap.GenerateOfflineMapResult;
import com.esri.arcgisruntime.tasks.offlinemap.OfflineMapTask;

public class GenerateOfflineMapSample extends Application {

  private MapView mapView;

  @Override
  public void start(Stage stage) {

    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("Generate Offline Map Sample");
      stage.setWidth(800);
      stage.setHeight(700);
      stage.setScene(scene);
      stage.show();

      // create a button to take the map offline
      Button offlineMapButton = new Button("Take Map Offline");
      offlineMapButton.setDisable(true);

      // handle authentication with the portal
      AuthenticationManager.setAuthenticationChallengeHandler(new DefaultAuthenticationChallengeHandler());

      // create a portal item with the itemId of the web map
      Portal portal = new Portal("https://www.arcgis.com", true);
      PortalItem portalItem = new PortalItem(portal, "acc027394bc84c2fb04d1ed317aac674");

      // create a map with the portal item
      ArcGISMap map = new ArcGISMap(portalItem);
      map.addDoneLoadingListener(() -> {
        // enable the button when the map is loaded
        if (map.getLoadStatus() == LoadStatus.LOADED) {
          offlineMapButton.setDisable(false);
        }
      });

      // set the map to the map view
      mapView = new MapView();
      mapView.setMap(map);

      // create a graphics overlay for the map view
      GraphicsOverlay graphicsOverlay = new GraphicsOverlay();
      mapView.getGraphicsOverlays().add(graphicsOverlay);

      // create a graphic to show a box around the extent we want to download
      Graphic downloadArea = new Graphic();
      graphicsOverlay.getGraphics().add(downloadArea);
      SimpleLineSymbol simpleLineSymbol = new SimpleLineSymbol(SimpleLineSymbol.Style.SOLID, 0xFFFF0000, 2);
      downloadArea.setSymbol(simpleLineSymbol);

      // update the box whenever the viewpoint changes
      mapView.addViewpointChangedListener(viewpointChangedEvent -> {
        if (map.getLoadStatus() == LoadStatus.LOADED) {
          // upper left corner of the area to take offline
          Point2D minScreenPoint = new Point2D(50, 50);
          // lower right corner of the downloaded area
          Point2D maxScreenPoint = new Point2D(mapView.getWidth() - 50, mapView.getHeight() - 50);
          // convert screen points to map points
          Point minPoint = mapView.screenToLocation(minScreenPoint);
          Point maxPoint = mapView.screenToLocation(maxScreenPoint);
          // use the points to define and return an envelope
          if (minPoint != null && maxPoint != null) {
            Envelope envelope = new Envelope(minPoint, maxPoint);
            downloadArea.setGeometry(envelope);
          }
        }
      });

      // create progress bar to show download progress
      ProgressBar progressBar = new ProgressBar();
      progressBar.setProgress(0.0);
      progressBar.setVisible(false);

      // when the button is clicked, start the offline map task job
      offlineMapButton.setOnAction(e -> {
        try {
          // show the progress bar
          progressBar.setVisible(true);

          // specify the extent, min scale, and max scale as parameters
          double minScale = mapView.getMapScale();
          double maxScale = map.getMaxScale();
          // minScale must always be larger than maxScale
          if (minScale <= maxScale) {
            minScale = maxScale + 1;
          }
          GenerateOfflineMapParameters params = new GenerateOfflineMapParameters(downloadArea.getGeometry(), minScale, maxScale);

          // create an offline map task with the map
          OfflineMapTask task = new OfflineMapTask(map);

          // create an offline map job with the download directory path and parameters and start the job
          Path tempDirectory = Files.createTempDirectory("offline_map");
          GenerateOfflineMapJob job = task.generateOfflineMap(params, tempDirectory.toAbsolutePath().toString());
          job.start();
          job.addJobDoneListener(() -> {
            if (job.getStatus() == Job.Status.SUCCEEDED) {
              // replace the current map with the result offline map when the job finishes
              GenerateOfflineMapResult result = job.getResult();
              mapView.setMap(result.getOfflineMap());
              graphicsOverlay.getGraphics().clear();
              offlineMapButton.setDisable(true);
            } else {
              new Alert(Alert.AlertType.ERROR, job.getError().getAdditionalMessage()).show();
            }
            Platform.runLater(() -> progressBar.setVisible(false));
          });
          // show the job's progress with the progress bar
          job.addProgressChangedListener(() -> progressBar.setProgress(job.getProgress() / 100.0));
        } catch (IOException ex) {
          new Alert(Alert.AlertType.ERROR, "Failed to create temporary directory").show();
        }
      });

      // add the map view, button, and progress bar to stack pane
      stackPane.getChildren().addAll(mapView, offlineMapButton, progressBar);
      StackPane.setAlignment(offlineMapButton, Pos.TOP_LEFT);
      StackPane.setAlignment(progressBar, Pos.TOP_RIGHT);
    } catch (Exception e) {
      // on any error, display the stack trace.
      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);
  }

}


In this topic
  1. How it works
  2. Code