Fetching Weather Data From Yahoo With JavaFX

 Do you remember the Hello World, JavaFX style application? It prints the text "Hello World!" to the output window when you click a button. I changed it to print the temperature in Bucharest instead:

First version:

package helloworld;

import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.StackPane;
import javafx.scene.web.WebEngine;
import javafx.stage.Stage;

import org.w3c.dom.*;

/**
 *
 * @author Cristina
 */
public class HelloWorld extends Application {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }
   
    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("Hello World!");
       
        final WebEngine webEngine = new WebEngine("http://weather.yahooapis.com/forecastrss?w=868274&u=c");
      
        Button btn = new Button();
        btn.setText("Say 'Hello World'");
        btn.setOnAction(new EventHandler() {

            @Override
            public void handle(ActionEvent event) {
                NodeList meteo = webEngine.getDocument().getElementsByTagNameNS("http://xml.weather.yahoo.com/ns/rss/1.0", "condition");
                System.out.println(meteo
                .item(0)
                .getAttributes()
                .getNamedItem("temp")
                .getNodeValue()
                .toString());
            }
        });
       
        StackPane root = new StackPane();
        root.getChildren().add(btn);
        primaryStage.setScene(new Scene(root, 300, 250));
        primaryStage.show();
    }   
}

Second version:

public class HelloWorld extends Application {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        launch(args);
    }
   
    @Override
    public void start(Stage primaryStage) {
        primaryStage.setTitle("Fetching Weather Data From Yahoo");
        Group root = new Group();
        Scene scene = new Scene(root, 400, 100);
               
        final WebEngine webEngine = new WebEngine("http://weather.yahooapis.com/forecastrss?w=868274&u=c");
      
        Button btn = new Button();
        btn.setText("Get temperature");
       
        final Text temperatura = new Text(10,50,"Temperatura in Bucuresti");
       
        btn.setOnAction(new EventHandler() {

            @Override
            public void handle(ActionEvent event) {
                NodeList meteo = webEngine.getDocument().getElementsByTagNameNS("http://xml.weather.yahoo.com/ns/rss/1.0", "condition");
                temperatura.setText("Hi! The temperature in Bucharest is: " + meteo
                .item(0)
                .getAttributes()
                .getNamedItem("temp")
                .getNodeValue()
                .toString() + " degrees Celsius.");
            }
        });
       
        root.getChildren().add(btn);
        root.getChildren().add(temperatura);
       
        primaryStage.setScene(scene);
        primaryStage.show();
    }

}
 

Bibliography

1. http://developer.yahoo.com/weather/#request
2. JavaFX 2.0: Introduction by Example, by Carl Dea