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
ServiceFeatureTableusing the URL of a feature service. - Create a
QueryParameterswith a where clause specified usingsetWhereClause(). - Perform the query using
queryFeaturesAsync(query)on the service feature table. - When complete, the query will return a
FeatureQueryResultwhich 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
FeatureLayerQuerySample.java
/* * 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.Color; 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 to golden color for the US states with a black color outline SimpleLineSymbol lineSymbol = new SimpleLineSymbol(SimpleLineSymbol.Style.SOLID, Color.BLACK, 1); SimpleFillSymbol fillSymbol = new SimpleFillSymbol(SimpleFillSymbol.Style.SOLID, Color.DARKGOLDENROD, 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); } }