使用JFreeChart上下拖动点后获取值

import org.jfree.chart.*;
import org.jfree.chart.entity.*;
import org.jfree.chart.plot.*;
import org.jfree.data.xy.*;
import org.jfree.ui.*;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class DragPointExample extends JFrame {

    private XYSeries series;
    private XYSeriesCollection dataset;
    private JFreeChart chart;
    private ChartPanel chartPanel;

    public DragPointExample() {
        super("Drag Point Example");

        // 创建数据集对象
        series = new XYSeries("Data");
        dataset = new XYSeriesCollection(series);

        // 创建图表对象
        chart = ChartFactory.createXYLineChart(
                "Drag Point Example", // 标题
                "X", // X轴标签
                "Y", // Y轴标签
                dataset, // 数据集
                PlotOrientation.VERTICAL, // 图表方向
                true, // 是否显示图例
                true, // 是否生成工具提示
                false // 是否生成URL链接
        );

        // 创建绘图区域对象
        XYPlot plot = chart.getXYPlot();

        // 创建图表面板对象
        chartPanel = new ChartPanel(chart);
        chartPanel.setPreferredSize(new Dimension(500, 300));

        // 添加鼠标事件监听器
        chartPanel.addChartMouseListener(new ChartMouseListener() {
            @Override
            public void chartMouseClicked(ChartMouseEvent event) {
                // 处理鼠标点击事件
            }

            @Override
            public void chartMouseMoved(ChartMouseEvent event) {
                // 处理鼠标移动事件
                ChartEntity entity = event.getEntity();
                if (entity instanceof XYItemEntity) {
                    XYItemEntity itemEntity = (XYItemEntity) entity;
                    XYDataset dataset = itemEntity.getDataset();
                    int seriesIndex = itemEntity.getSeriesIndex();
                    int itemIndex = itemEntity.getItem();
                    double x = dataset.getXValue(seriesIndex, itemIndex);
                    double y = dataset.getYValue(seriesIndex, itemIndex);
                    System.out.println("X: " + x + ", Y: " + y);
                }
            }
        });

        // 添加图表面板到窗口
        setContentPane(chartPanel);
        pack();
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationRelativeTo(null);
    }

    public void addData(double x, double y) {
        series.add(x, y);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            DragPointExample example = new DragPointExample();
            example.setVisible(true);
            example.addData(1.0, 2.0);
            example.addData(2.0, 3.0);
            example.addData(3.0, 4.0);
        });
    }
}