Find features in a feature table which match an SQL query.
Use case
Query expressions can be used in ArcGIS to select a subset of features from a feature table. This is most useful in large or complicated data sets. A possible use case might be on a feature table marking the location of street furniture through a city. A user may wish to query by a TYPE column to return "benches". In this sample, we query a U.S. state by STATE_NAME from a feature table containing all U.S. states.
How to use the sample
Input the name of a U.S. state into the text field. When you click "Search", a query is performed and the matching features are highlighted or an error is returned.
How it works
- Create a
ServiceFeatureTable
using the URL of a feature service. - Create a
QueryParameters
with a where clause specified usingsetWhereClause()
. - Perform the query using
queryFeaturesAsync(query)
on the service feature table. - When complete, the query will return a
FeatureQueryResult
which can be iterated over to get the matching features.
About the data
This sample uses U.S. State polygon features from the USA 2016 Daytime Population feature service.
Relevant API
- FeatureLayer
- FeatureQueryResult
- QueryParameters
- ServiceFeatureTable
Tags
search
Sample Code
/*
* Copyright 2017 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.feature_layer_query;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.control.Alert.AlertType;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.Background;
import javafx.scene.layout.BackgroundFill;
import javafx.scene.layout.CornerRadii;
import javafx.scene.layout.HBox;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Paint;
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.QueryParameters;
import com.esri.arcgisruntime.data.ServiceFeatureTable;
import com.esri.arcgisruntime.geometry.Envelope;
import com.esri.arcgisruntime.geometry.Point;
import com.esri.arcgisruntime.geometry.SpatialReferences;
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.MapView;
import com.esri.arcgisruntime.symbology.SimpleFillSymbol;
import com.esri.arcgisruntime.symbology.SimpleLineSymbol;
import com.esri.arcgisruntime.symbology.SimpleRenderer;
public class FeatureLayerQuerySample extends Application {
private Alert dialog;
private MapView mapView;
private FeatureLayer featureLayer;
private ServiceFeatureTable featureTable;
private Point startPoint;
private ListenableFuture<FeatureQueryResult> tableQueryResult;
private final int SCALE = 100000000;
@Override
public void start(Stage stage) {
try {
// create stack pane and application scene
StackPane stackPane = new StackPane();
Scene scene = new Scene(stackPane);
scene.getStylesheets().add(getClass().getResource("/feature_layer_query/style.css").toExternalForm());
// set title, size, and add scene to stage
stage.setTitle("Feature Layer Query 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 a control panel
VBox controlsVBox = new VBox(6);
controlsVBox.setBackground(new Background(new BackgroundFill(Paint.valueOf("rgba(0,0,0,0.3)"), CornerRadii.EMPTY,
Insets.EMPTY)));
controlsVBox.setPadding(new Insets(10.0));
controlsVBox.setMaxSize(250, 80);
controlsVBox.getStyleClass().add("panel-region");
// create area for searching
Label searchLabel = new Label("Search for a State:");
searchLabel.getStyleClass().add("panel-label");
TextField searchField = new TextField();
searchField.setMaxWidth(150);
Button searchButton = new Button("Search");
HBox searchBox = new HBox(5);
searchBox.getChildren().addAll(searchField, searchButton);
searchBox.setDisable(true);
// create dialog to display alert information
dialog = new Alert(AlertType.WARNING);
// search for the state that was entered
searchButton.setOnAction(e -> {
// clear the selection of the feature
featureLayer.clearSelection();
String stateText = searchField.getText();
if (stateText.trim().length() > 0) {
searchForState(stateText);
} else {
dialog.setContentText("State Not Found! Add a valid state name.");
dialog.showAndWait();
mapView.setViewpointCenterAsync(startPoint, SCALE);
}
});
// add search label and box to the control panel
controlsVBox.getChildren().addAll(searchLabel, searchBox);
// create a starting point for the view
startPoint = new Point(-11000000, 5000000, SpatialReferences.getWebMercator());
// set fill orange (0xFFFFCC00) color for the US states with a black color
// (0xFF000000) outline
SimpleLineSymbol lineSymbol = new SimpleLineSymbol(SimpleLineSymbol.Style.SOLID, 0xFF000000, 1);
SimpleFillSymbol fillSymbol = new SimpleFillSymbol(SimpleFillSymbol.Style.SOLID, 0xFFFFCC00, lineSymbol);
// create a service feature table
featureTable = new ServiceFeatureTable("https://services.arcgis.com/jIL9msH9OI208GCb/arcgis/rest/services/USA_Daytime_Population_2016/FeatureServer/0");
// create a feature layer from table
featureLayer = new FeatureLayer(featureTable);
featureLayer.setOpacity(0.8f);
featureLayer.setMaxScale(10000);
// enable search once the feature layer is loaded
featureLayer.addDoneLoadingListener(() -> {
if (featureLayer.getLoadStatus() == LoadStatus.LOADED) {
searchBox.setDisable(false);
} else {
Alert alert = new Alert(Alert.AlertType.ERROR, "Feature Layer Failed to Load!");
alert.show();
}
});
// set renderer for feature layer
featureLayer.setRenderer(new SimpleRenderer(fillSymbol));
// create a map with the topographic basemap style
final ArcGISMap map = new ArcGISMap(BasemapStyle.ARCGIS_TOPOGRAPHIC);
// create a map view and set the map to it
mapView = new MapView();
mapView.setMap(map);
// add the feature layer to the map's operational layers
map.getOperationalLayers().add(featureLayer);
// set viewpoint to the start point
mapView.setViewpointCenterAsync(startPoint, SCALE);
// add the map view and control panel to stack pane
stackPane.getChildren().addAll(mapView, controlsVBox);
StackPane.setAlignment(controlsVBox, Pos.TOP_LEFT);
StackPane.setMargin(controlsVBox, new Insets(10, 0, 0, 10));
} catch (Exception e) {
// on any error, display the stack trace
e.printStackTrace();
}
}
/**
* Searches for a US state inside the current ServiceFeatureTable.
*
* @param state a US state that is being searched
*/
private void searchForState(String state) {
// create a query for the state that was entered
QueryParameters query = new QueryParameters();
query.setWhereClause("upper(STATE_NAME) LIKE '" + state.toUpperCase() + "'");
// search for the state feature in the feature table
tableQueryResult = featureTable.queryFeaturesAsync(query);
tableQueryResult.addDoneListener(() -> {
try {
// get the result from the query
FeatureQueryResult result = tableQueryResult.get();
// if a state feature was found
if (result.iterator().hasNext()) {
// get state feature and zoom to it
Feature feature = result.iterator().next();
Envelope envelope = feature.getGeometry().getExtent();
mapView.setViewpointGeometryAsync(envelope, 200);
// set the state feature to be selected
featureLayer.selectFeature(feature);
} else {
Platform.runLater(() -> {
dialog.setContentText("State Not Found! Add a valid state name.");
dialog.showAndWait();
mapView.setViewpointCenterAsync(startPoint, SCALE);
});
}
} 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);
}
}