从Javafx中的另一个Java类访问一个Java类

Question

I am unable to call a class from another class in my javafx application. I make a pie-graph in java. When called individually this runs successfully. But when I use this code through access from another class from this current class using this code

Graph main = new Graph();
Application.launch();

it is not working.

And this is the graph code being called from the above, sitting in its own class.

package semi_final1;
//package Graph;
import javafx.application.Application;
import static javafx.application.Application.launch;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.stage.Stage;
import javafx.scene.chart.*;
import javafx.scene.Group;
/**
 *
 * @author 
 */
public class Graph extends Application {
  @Override public void start(Stage stage) {
        Scene scene = new Scene(new Group());
        stage.setTitle("Analysis");
        stage.setWidth(500);
        stage.setHeight(500);
      ObservableList<PieChart.Data> pieChartData =
                FXCollections.observableArrayList(
                new PieChart.Data("Levels", 13),
                new PieChart.Data("Points", 25),
                new PieChart.Data("Questions", 10),
                new PieChart.Data("Answers", 22),
                new PieChart.Data("Length of Contents", 20),
                 new PieChart.Data("Likes", 20),
                new PieChart.Data("Dislikes", 10),
                 new PieChart.Data("Jaccard", 10));
        final PieChart chart = new PieChart(pieChartData);
        chart.setTitle("Imported Fruits");

        ((Group) scene.getRoot()).getChildren().add(chart);
        stage.setScene(scene);
        stage.show();
    }

    public static void main(String[] args) {
        //launch(args);
    }
}

Answer 1

Application.launch(String...) only works, if called from a class that extends application (and that class will be used as the Application 's class). If you want to start a javafx application from a different class, you need to use the Application.launch(Class, String... method:

Application.launch(Graph.class);

Note that you must not start more than 1 Application from the same program.

(Move the code of the scene graph, ect. to different classes if you're planning to do this; eg using fxml+controller would be a good idea in that case)