求jfreechart 折线图问题，急！

Question

我想用jfreechart做一个折线图，要求横轴是日1期，竖轴是数量。横轴日期为每个月的所有天数。如1月是1-31日，则页面上是31个点的折线图。根据每个月天数不同横轴坐标有不同的天数，问怎样实现？有样例代码也可以。谢谢了。

Answer 1

给你一个例子，参考着改改就行了。jfc_0.9
package org.jfree.chart.demo;import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Polygon;
import java.awt.Shape;
import java.awt.geom.Rectangle2D;import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.DefaultDrawingSupplier;
import org.jfree.chart.plot.DrawingSupplier;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.category.LineAndShapeRenderer;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.category.DefaultCategoryDataset;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.RefineryUtilities;/**
 * A line chart demo showing the use of a custom drawing supplier.
 *
 */
public class LineChartDemo5 extends ApplicationFrame {    /**
     * Creates a new demo.
     *
     * @param title  the frame title.
     */
    public LineChartDemo5(final String title) {
        super(title);
        final CategoryDataset dataset = createDataset();
        final JFreeChart chart = createChart(dataset);
        final ChartPanel chartPanel = new ChartPanel(chart);
        chartPanel.setPreferredSize(new java.awt.Dimension(500, 270));
        setContentPane(chartPanel);    }
    
    /**
     * Creates a sample dataset.
     * 
     * @return a sample dataset.
     */
    private CategoryDataset createDataset() {
        
        // row keys...
        final String series1 = "First";
        final String series2 = "Second";
        final String series3 = "Third";        // column keys...
        final String type1 = "Type 1";
        final String type2 = "Type 2";
        final String type3 = "Type 3";
        final String type4 = "Type 4";
        final String type5 = "Type 5";
        final String type6 = "Type 6";
        final String type7 = "Type 7";
        final String type8 = "Type 8";        // create the dataset...
        final DefaultCategoryDataset dataset = new DefaultCategoryDataset();        dataset.addValue(1.0, series1, type1);
        dataset.addValue(4.0, series1, type2);
        dataset.addValue(3.0, series1, type3);
        dataset.addValue(5.0, series1, type4);
        dataset.addValue(5.0, series1, type5);
        dataset.addValue(7.0, series1, type6);
        dataset.addValue(7.0, series1, type7);
        dataset.addValue(8.0, series1, type8);        dataset.addValue(5.0, series2, type1);
        dataset.addValue(7.0, series2, type2);
        dataset.addValue(6.0, series2, type3);
        dataset.addValue(8.0, series2, type4);
        dataset.addValue(4.0, series2, type5);
        dataset.addValue(4.0, series2, type6);
        dataset.addValue(2.0, series2, type7);
        dataset.addValue(1.0, series2, type8);        dataset.addValue(4.0, series3, type1);
        dataset.addValue(3.0, series3, type2);
        dataset.addValue(2.0, series3, type3);
        dataset.addValue(3.0, series3, type4);
        dataset.addValue(6.0, series3, type5);
        dataset.addValue(3.0, series3, type6);
        dataset.addValue(4.0, series3, type7);
        dataset.addValue(3.0, series3, type8);
           
        return dataset;
        
    }    /**
     * Creates a sample chart.
     * 
     * @param dataset  the dataset.
     * 
     * @return a chart.
     */    
    private JFreeChart createChart(final CategoryDataset dataset) {        final JFreeChart chart = ChartFactory.createLineChart(
            "Line Chart Demo 5",      // chart title
            "Type",                   // domain axis label
            "Value",                  // range axis label
            dataset,                  // data
            PlotOrientation.VERTICAL, // orientation
            true,                     // include legend
            true,                     // tooltips
            false                     // urls
        );//        final StandardLegend legend = (StandardLegend) chart.getLegend();
  //      legend.setDisplaySeriesShapes(true);        final Shape[] shapes = new Shape[3];
        int[] xpoints;
        int[] ypoints;        // right-pointing triangle
        xpoints = new int[] {-3, 3, -3};
        ypoints = new int[] {-3, 0, 3};
        shapes[0] = new Polygon(xpoints, ypoints, 3);        // vertical rectangle
        shapes[1] = new Rectangle2D.Double(-2, -3, 3, 6);        // left-pointing triangle
        xpoints = new int[] {-3, 3, 3};
        ypoints = new int[] {0, -3, 3};
        shapes[2] = new Polygon(xpoints, ypoints, 3);        final DrawingSupplier supplier = new DefaultDrawingSupplier(
            DefaultDrawingSupplier.DEFAULT_PAINT_SEQUENCE,
            DefaultDrawingSupplier.DEFAULT_OUTLINE_PAINT_SEQUENCE,
            DefaultDrawingSupplier.DEFAULT_STROKE_SEQUENCE,
            DefaultDrawingSupplier.DEFAULT_OUTLINE_STROKE_SEQUENCE,
            shapes
        );
        final CategoryPlot plot = chart.getCategoryPlot();
        plot.setDrawingSupplier(supplier);        chart.setBackgroundPaint(Color.yellow);        // set the stroke for each series...
        plot.getRenderer().setSeriesStroke(
            0, 
            new BasicStroke(
                2.0f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND, 
                1.0f, new float[] {10.0f, 6.0f}, 0.0f
            )
        );
        plot.getRenderer().setSeriesStroke(
            1, 
            new BasicStroke(
                2.0f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND,
                1.0f, new float[] {6.0f, 6.0f}, 0.0f
            )
        );
        plot.getRenderer().setSeriesStroke(
            2, 
            new BasicStroke(
                2.0f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND,
                1.0f, new float[] {2.0f, 6.0f}, 0.0f
            )
        );        // customise the renderer...
        final LineAndShapeRenderer renderer = (LineAndShapeRenderer) plot.getRenderer();
//        renderer.setDrawShapes(true);
        renderer.setItemLabelsVisible(true);
  //      renderer.setLabelGenerator(new StandardCategoryLabelGenerator());        // customise the range axis...
        final NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis();
        rangeAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
        rangeAxis.setAutoRangeIncludesZero(false);
        rangeAxis.setUpperMargin(0.12);        return chart;
        
    }    // ****************************************************************************
    // * JFREECHART DEVELOPER GUIDE                                               *
    // * The JFreeChart Developer Guide, written by David Gilbert, is available   *
    // * to purchase from Object Refinery Limited:                                *
    // *                                                                          *
    // * http://www.object-refinery.com/jfreechart/guide.html                     *
    // *                                                                          *
    // * Sales are used to provide funding for the JFreeChart project - please    * 
    // * support us so that we can continue developing free software.             *
    // ****************************************************************************
    
   /**
     * Starting point for the demonstration application.
     *
     * @param args  ignored.
     */
    public static void main(final String[] args) {        final LineChartDemo5 demo = new LineChartDemo5("Line Chart Demo 5");
        demo.pack();
        RefineryUtilities.centerFrameOnScreen(demo);
        demo.setVisible(true);    }}
           

Answer 2

是的，一条线上31个点。
这个例子好像不行吧，我试过，addValue很多值但最多只能显示12个，不知道为什么。

Answer 3

啊？addValue只能加12个点？
这个确实还没试过。
再研究研究

Answer 4

不好意思，是我自己的一个去年月的算法写错了。感谢denghan(很久没来ASP版了)