对象的 Javafx 线图

Question

我有一个对象 DataEntry 定义如下:

public class DataEntry {

private long timestamp;
private double value;

public DataEntry(long timestamp, double value) {
    this.timestamp = timestamp;
    this.value = value;
}

public long getTimeStamp() {
    return timestamp;
}

public double getValue() {
    return value;
}

我想用 X 中的时间戳和 Y 中的值生成这些元素的 LineChart。但是我在 Internet 上找不到任何关于此的教程(也许我正在尝试做不可能的事)。

对我来说最好的情况是 LineChart 构造函数，它将 DataEntry 的 ArrayList 作为参数，因为我想集成它图表到场景。

以下是我走了多远，但我无法执行我的程序。

public class DataEntryChart extends Application {

private String title;
private ArrayList<DataEntry> entries;

public DataEntryChart(String title, ArrayList<DataEntry> entries){
    this.title=title;
    this.entries=entries;
}

@Override public void start(Stage stage) {
    stage.setTitle(this.title);
    final NumberAxis xAxis = new NumberAxis();
    final NumberAxis yAxis = new NumberAxis();
    xAxis.setLabel("Date");       

    final LineChart<Number,Number> lineChart = 
            new LineChart<Number,Number>(xAxis,yAxis);               

    Series series = new XYChart.Series<Long,Double>();      

    for(DataEntry d : this.entries){
        series.getData().add(new XYChart.Data(d.getTimeStamp(),d.getValue()));
    }

    Scene scene  = new Scene(lineChart,800,600);
    lineChart.getData().add(series);


    stage.setScene(scene);
    stage.show();
}

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

如果这不可能，我想知道是否有一种方法可以根据参数创建折线图，例如

new LineChart(int[] x, int[]y)

并且能够将其集成到场景中。

Answer 1

我设法让一个解决方案工作，我使用 Controller 将这些值作为属性传递(即使我可以不用我只是想将它作为一个属性以确保我仍然可以在这个方法之外访问它)

public class GraphListener {

    ArrayList<DataEntry> entries = new ArrayList<DataEntry>();

    @FXML
    private Button updateButton;
    @FXML
    private ComboBox<String> propertiesCombo;
    @FXML
    private Button generateButton;
    @FXML
    private LineChart<Number, Number> dataChart;
    @FXML
    private TextArea statsTextArea;

    @FXML
    protected void handleUpdateButtonAction(ActionEvent event) {
        HBaseClient client = new HBaseClient();
        client.makeConnection();
        ArrayList<String> properties = client.getColumnName("demo");

        propertiesCombo.getItems().clear();
        propertiesCombo.getItems().addAll(properties);

        client.disconnect();
    }

    @FXML
    protected void handleGenerateButtonAction(ActionEvent event) {
        // Retrieving data
        String property = propertiesCombo.getSelectionModel().getSelectedItem();

        HBaseClient client = new HBaseClient();
        client.makeConnection();
        this.entries = client.scan("demo", "data", property);
        client.disconnect();

        // Filling the text area
        statsTextArea.clear();
        statsTextArea.appendText("Number of elements : " + handler.numberOfElements()+"\n");
        statsTextArea.appendText("Mean : " + handler.mean()+"\n");
        statsTextArea.appendText("Geometric mean : " + handler.geometricMean()+"\n");
        statsTextArea.appendText("Minimal value : " + handler.min()+"\n");
        statsTextArea.appendText("Maximal value : " + handler.max()+"\n");

        // Generating the graph

        dataChart.setTitle("Evolution of "+property);


        Series<Number, Number> series = new XYChart.Series<Number, Number>();
        series.setName(property);
        ArrayList<Long> timestamps = new ArrayList<Long>();
        for (DataEntry d : this.entries) {
            series.getData().add(new Data<Number, Number>(d.getTimeStamp(), d.getValue()));
            timestamps.add(d.getTimeStamp());
        }
        dataChart.getXAxis().setLabel("Timestamp");
        dataChart.getYAxis().setLabel("Values");
        dataChart.getData().add(series);

    }

}