java导出虚线折线图

您可以使用JFreeChart库来创建Java中的虚线折线图。以下是一个简单的示例代码：

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.GradientPaint;
import java.awt.Paint;
import java.awt.Point;
import java.awt.Shape;
import java.awt.Stroke;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Rectangle2D;
import javax.swing.JFrame;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.category.LineAndShapeRenderer;
import org.jfree.data.category.DefaultCategoryDataset;

public class DashedLineChartExample extends JFrame {

    public DashedLineChartExample(String title) {
        super(title);

        // Create dataset
        DefaultCategoryDataset dataset = createDataset();

        // Create chart
        JFreeChart chart = ChartFactory.createLineChart(
                "Dashed Line Chart Example",
                "Category",
                "Value",
                dataset,
                PlotOrientation.VERTICAL,
                true, // Legend
                true, // Tooltips
                false // URLs
        );

        // Set background color
        chart.setBackgroundPaint(Color.WHITE);

        // Get plot
        CategoryPlot plot = (CategoryPlot) chart.getPlot();

        // Set background color
        plot.setBackgroundPaint(Color.LIGHT_GRAY);
        plot.setRangeGridlinePaint(Color.WHITE);

        // Set renderer
        LineAndShapeRenderer renderer = new LineAndShapeRenderer() {
            // Override getItemShape() method to return a circle shape
            @Override
            public Shape getItemShape(int row, int col) {
                return new Ellipse2D.Double(-3.0, -3.0, 6.0, 6.0);
            }

            // Override getItemPaint() method to return a gradient paint
            @Override
            public Paint getItemPaint(int row, int col) {
                GradientPaint gradient = new GradientPaint(
                        0.0f, 0.0f, Color.BLUE,
                        0.0f, 0.0f, Color.LIGHT_GRAY
                );
                return gradient;
            }

            // Override getItemStroke() method to return a dashed stroke
            @Override
            public Stroke getItemStroke(int row, int col) {
                return new BasicStroke(
                        1.0f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND,
                        1.0f, new float[]{6.0f, 6.0f}, 0.0f
                );
            }
        };
        plot.setRenderer(renderer);

        // Set chart dimensions
        ChartPanel chartPanel = new ChartPanel(chart);
        chartPanel.setPreferredSize(new Dimension(500, 300));
        setContentPane(chartPanel);
    }

    private DefaultCategoryDataset createDataset() {
        DefaultCategoryDataset dataset = new DefaultCategoryDataset();

        dataset.addValue(2.0, "Series 1", "Category 1");
        dataset.addValue(4.0, "Series 1", "Category 2");
        dataset.addValue(3.0, "Series 1", "Category 3");
        dataset.addValue(5.0, "Series 1", "Category 4");
        dataset.addValue(6.0, "Series 1", "Category 5");

        return dataset;
    }

    public static void main(String[] args) {
        DashedLineChartExample example = new DashedLineChartExample("Dashed Line Chart Example");
        example.pack();
        example.setLocationRelativeTo(null);
        example.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        example.setVisible(true);
    }
}

在上面的示例中，我们使用`LineAndShapeRenderer`来设置虚线和圆形点。要设置虚线，我们需要覆盖`getItemStroke()`方法，并使用`new float[] {6.0f, 6.0f}`来定义虚线的长度和间隔。最后，我们将渲染器设置为绘制虚线和圆形点。

您可以根据自己的需求更改示例中的数据集和其他属性。