I've tried to write a graphic interface to my DataFrame project. I have to read DataFrame from file and then I want to count for example min for each column. I have an open button, so I can read a file, but I don't know how can I work on this file(if you know what I mean). When I tried to press min botton, there was a null pointer exception. I guess that the dataframe is empty. But what should I do to fix it? I also have to draw a graphs, but I totally do not know how to do it.
public class Graphics extends Application {
private Text actionStatus;
private Stage savedStage;
DataFrame d;
public static void main(String[] args) {
Application.launch(args);
}
@Override
public void start(Stage primaryStage) {
Button open = new Button("open");
open.setOnAction(new SingleFcButtonListener());
HBox open1 = new HBox(10);
open1.getChildren().addAll(open);
Button save = new Button("Save");
HBox save1 = new HBox(10);
save1.getChildren().addAll(save);
Button min = new Button("Min");
HBox min1 = new HBox(10);
min1.getChildren().addAll(min);
min.setOnAction(new SingleButtonListener());
actionStatus = new Text();
VBox vbox = new VBox(30);
vbox.getChildren().addAll( open1,save1, min, actionStatus);
Scene scene = new Scene(vbox, 500, 300);
primaryStage.setScene(scene);
primaryStage.show();
savedStage = primaryStage;
}
private class SingleFcButtonListener implements EventHandler<ActionEvent> {
@Override
public void handle(ActionEvent e) {
showSingleFileChooser();
}
}
private void showSingleFileChooser() {
FileChooser fileChooser = new FileChooser();
File selectedFile = fileChooser.showOpenDialog(null);
if (selectedFile != null) {
actionStatus.setText("File selected: " + selectedFile.getName());
ArrayList<Class<? extends Value>> arr2 = new ArrayList<Class<? extends Value>>();
arr2.add(Str.class);
arr2.add(DateTime.class);
arr2.add(com.projekt1.Double.class);
arr2.add(Double.class);
DataFrame d = new DataFrame(selectedFile.getName(), arr2, true);
d.showDatabase();
}
}
private class SingleButtonListener implements EventHandler<ActionEvent> {
@Override
public void handle(ActionEvent e) {
showMean();
}
}
private void showMean() {
d.mindf().showDatabase();
}
}
