JFreeChart 点击图表XY系列坐标

Question

当用户单击 JFreeChart 提供的 XY 系列图表的点之一时，我试图分别获取 x 和 y 坐标。此外，我正在使用 Java 编程语言在 servlet 中执行此操作。 List 是我从模型包中制作的对象，该模型包具有类称为 Home 和 Away。请随时询问有关 servlet 的更多信息，因为我在下面提供了代码。

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // Object saved in application scopes two list one fore Home and Away   

        List<Home> forumi = (List<Home>) getServletContext().getAttribute(
                "home" );

        List<Away> forumi2 = (List<Away>) getServletContext().getAttribute(
                "away" );

        OutputStream out = response.getOutputStream(); 

        try {
            //creating an XY dataset
             XYSeriesCollection dataset = new XYSeriesCollection();
                XYSeries series1 = new XYSeries("Home");
                XYSeries series2 = new XYSeries("Away");

        //inputing data to chart
        int counter = 1;
        for(int i=0; i < forumi.size(); i++) {
            series1.add(counter, forumi.get(i).getScores());
            ++counter;
        }

        int counter2 = 1;
        for(int i=0; i < forumi2.size(); i++) {
            series2.add(counter2, forumi2.get(i).getScores());
            ++counter2;
        }

        dataset.addSeries(series1);
        dataset.addSeries(series2);
        /* create chart */
        String chartTitle = "2019-2020";
        String xAxisLabel = "game";
        String yAxisLabel = "Scores";

        JFreeChart chart = ChartFactory.createXYLineChart(chartTitle,
                xAxisLabel, yAxisLabel, dataset);

        //Customize chart
         XYPlot plot = chart.getXYPlot();
         XYLineAndShapeRenderer renderer = new XYLineAndShapeRenderer();
        // sets thickness for series (using strokes)
         renderer.setSeriesPaint(0, Color.RED);
         renderer.setSeriesPaint(1, Color.BLUE);
        // sets paint color for each series
         renderer.setSeriesStroke(0, new BasicStroke(2.0f));
         renderer.setSeriesStroke(1, new BasicStroke(2.0f));
         //renderer.setSeriesStroke(1, new BasicStroke(3.0f));

         plot.setRenderer((XYItemRenderer) renderer);
         chartPanel = new ChartPanel(chart);   
        //System.out.print(plot.getRangeCrosshairValue()); 

        chart.getPlot().setBackgroundPaint(Color.WHITE);
        /* Set the HTTP Response Type */
        response.setContentType("image/png");

        /* Writes a chart to an output stream in PNG format */
        ChartUtilities.writeChartAsPNG(out, chart, 1704, 300);


        } catch (Exception e) {
        System.err.println(e.toString()); /* Throw exceptions to log files */
        } finally {
        out.close();/* Close the output stream */
        }
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    } ```

Answer 1

如此 example, you can create an HTML image map 所示，对应于图表中用于 servlet 上下文的实体。

在您选择的 ChartFactory 中将 tooltips 设置为 true 会添加一个 StandardXYToolTipGenerator，它将在鼠标移动事件上显示工具提示；将鼠标悬停在 scatter.html 中的实体上以查看效果；您可以自定义生成器，如图所示 here and here.

在您选择的 ChartFactory 中将 urls 设置为 true 添加一个 StandardXYURLGenerator，它将在鼠标单击事件中打开生成的 URL；使用自定义生成器点击 scatter.html 中的实体以查看效果：

chart.getXYPlot().getRenderer().setURLGenerator(new StandardXYURLGenerator(){
    @Override
    public String generateURL(XYDataset dataset, int series, int item) {
        return "http://example.com";
    }
});

对于 dataset、series 和 item.

的特定值，您的实际生成器可以 return 任何所需的 URL

JFreeChart 点击图表XY系列坐标

JFreeChart XY-series coordinates by clicking the chart

java

servlets

model-view-controller

controller

jfreechart