绘制图表时 JavaFX WeakReference 内存泄漏

Question

我遇到了内存泄漏，我无法在我的代码中修复它。场景:用户打开一个新窗口，其中绘制了一个图表(在本例中为折线图)。但是当窗口关闭时，java.lang.ref.WeakReference 和 javafx.beans.property.BooleanPropertyBase$Listener 留在内存中。它们的数量与绘制的数据点 (XYChart.Data) 完全对应。我只是不知道如何摆脱它们。在我的代码中，许多此类窗口频繁打开和关闭，每个图表有 10k-100k 数据点，内存很快就会被填满。

我确定我犯了一些愚蠢的错误，但我就是找不到它。将不胜感激!

示例代码:

import java.util.ArrayList;
import java.util.List;
import javafx.application.Application;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.control.Button;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

public class Test extends Application {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        Application.launch(Test.class, args);
    }

    @Override
    public void start(final Stage primaryStage) {
        primaryStage.setTitle("Hello World");
        Group root = new Group();
        Scene scene = new Scene(root, 300, 250, Color.LIGHTGREEN);
        Button btn = new Button();
        btn.setLayoutX(100);
        btn.setLayoutY(80);
        btn.setText("Create stage");
        btn.setOnAction(new EventHandler<ActionEvent>() {

            public void handle(ActionEvent event) {
                new CreateStage();
                primaryStage.toFront();

            }
        });
        root.getChildren().add(btn);
        primaryStage.setScene(scene);
        primaryStage.show();
    }
}

class CreateStage {

    public CreateStage() {
        Stage stage = new Stage();
            stage.setTitle("Line Chart Sample");
        //Basic Chart attributes
        NumberAxis xAxis = new NumberAxis();
        NumberAxis yAxis = new NumberAxis();
        xAxis.setLabel("RT [minutes]");
        yAxis.setLabel("Intensity");
        LineChart<Number, Number> linechart = new LineChart(xAxis, yAxis);

                XYChart.Series newSeries = new XYChart.Series();

                List<XYChart.Data> list = new ArrayList<>();
                //just fill the chart with data points
                for (int j = 0; j < 10000; j++) {
                    float intensity = j;
                    float currentRT = j;

                    list.add(new XYChart.Data(currentRT, intensity));
                }
                newSeries.getData().addAll(list);

                // add new Series
                linechart.getData().add(newSeries);

        Scene scene  = new Scene(linechart,800,600);       


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

Answer 1

我能够解决问题。呼唤

series.getData().clear();

关闭窗口时在每个 XYChart.Series 上消除内存泄漏。javafx.scene.layout.CornerRadii、com.sun.javafx.sg.prism.NGRegion 和javafx.scene.layout.Background 仍然保留在内存中，但最终会被垃圾收集并且不会堆积。

固定代码如下:

import java.util.ArrayList;
import java.util.List;
import javafx.application.Application;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.chart.LineChart;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.ScatterChart;
import javafx.scene.chart.XYChart;
import javafx.scene.control.Button;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

public class Test extends Application {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        Application.launch(Test.class, args);
    }

    @Override
    public void start(final Stage primaryStage) {
        primaryStage.setTitle("Hello World");
        Group root = new Group();
        Scene scene = new Scene(root, 300, 250, Color.LIGHTGREEN);
        Button btn = new Button();
        btn.setLayoutX(100);
        btn.setLayoutY(80);
        btn.setText("Create stage");
        btn.setOnAction(new EventHandler<ActionEvent>() {

            public void handle(ActionEvent event) {
                CreateStage();
                primaryStage.toFront();

            }
        });
        root.getChildren().add(btn);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

    public void CreateStage() {

        Stage stage = new Stage();
        stage.setTitle("Line Chart Sample");
        //Basic Chart attributes
        NumberAxis xAxis = new NumberAxis();
        NumberAxis yAxis = new NumberAxis();
        xAxis.setLabel("RT [minutes]");
        yAxis.setLabel("Intensity");

        //linechart.getData().clear();
        LineChart<Number, Number> linechart = new LineChart(xAxis, yAxis);

        XYChart.Series newSeries = new XYChart.Series();

        List<XYChart.Data> list = new ArrayList<>();
        //just fill the chart with data points
        for (int j = 0; j < 10000; j++) {
            float intensity = j;
            float currentRT = j;

            list.add(new XYChart.Data(currentRT, intensity));
        }
        newSeries.getData().addAll(list);

        // add new Series
        linechart.getData().add(newSeries);

        Scene scene = new Scene(linechart, 800, 600);

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

        //this fixes it
        stage.setOnCloseRequest(event -> {
            for (XYChart.Series series : linechart.getData()) {
                series.getData().clear();
            }

        });

    }
}

感谢@fabian 为我指明了正确的方向。