如何将jfree图表作为applet运行？

Question

I dont have much understanding in java but want the following code to run as applet. Request sincere help on this.

Can anyone help me running this code as applet? This is Jfree chart and i want to run it as an applet. Suggestion please.

package org.jfree.chart.demo;

import java.awt.Color;
import java.text.SimpleDateFormat;

import javax.swing.JPanel;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.ChartPanel;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.StandardChartTheme;
import org.jfree.chart.axis.DateAxis;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYItemRenderer;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.data.time.Month;
import org.jfree.data.time.TimeSeries;
import org.jfree.data.time.TimeSeriesCollection;
import org.jfree.data.xy.XYDataset;
import org.jfree.ui.ApplicationFrame;
import org.jfree.ui.RectangleInsets;
import org.jfree.ui.RefineryUtilities;

/**
 * An example of a time series chart.  For the most part, default settings are
 * used, except that the renderer is modified to show filled shapes (as well as
 * lines) at each data point.
 */
public class TimeSeriesChartDemo1 extends ApplicationFrame {

    private static final long serialVersionUID = 1L;

    {
        // set a theme using the new shadow generator feature available in
        // 1.0.14 - for backwards compatibility it is not enabled by default
        ChartFactory.setChartTheme(new StandardChartTheme("JFree/Shadow",
                true));
    }

    /**
     * A demonstration application showing how to create a simple time series
     * chart.  This example uses monthly data.
     *
     * @param title  the frame title.
     */
    public TimeSeriesChartDemo1(String title) {
        super(title);
        ChartPanel chartPanel = (ChartPanel) createDemoPanel();
        chartPanel.setPreferredSize(new java.awt.Dimension(500, 270));
        setContentPane(chartPanel);
    }

    /**
     * Creates a chart.
     *
     * @param dataset  a dataset.
     *
     * @return A chart.
     */
    private static JFreeChart createChart(XYDataset dataset) {

        JFreeChart chart = ChartFactory.createTimeSeriesChart(
            "Legal & General Unit Trust Prices",  // title
            "Date",             // x-axis label
            "Price Per Unit",   // y-axis label
            dataset,            // data
            true,               // create legend?
            true,               // generate tooltips?
            false               // generate URLs?
        );

        chart.setBackgroundPaint(Color.white);

        XYPlot plot = (XYPlot) chart.getPlot();
        plot.setBackgroundPaint(Color.lightGray);
        plot.setDomainGridlinePaint(Color.white);
        plot.setRangeGridlinePaint(Color.white);
        plot.setAxisOffset(new RectangleInsets(5.0, 5.0, 5.0, 5.0));
        plot.setDomainCrosshairVisible(true);
        plot.setRangeCrosshairVisible(true);

        XYItemRenderer r = plot.getRenderer();
        if (r instanceof XYLineAndShapeRenderer) {
            XYLineAndShapeRenderer renderer = (XYLineAndShapeRenderer) r;
            renderer.setBaseShapesVisible(true);
            renderer.setBaseShapesFilled(true);
            renderer.setDrawSeriesLineAsPath(true);
        }

        DateAxis axis = (DateAxis) plot.getDomainAxis();
        axis.setDateFormatOverride(new SimpleDateFormat("MMM-yyyy"));

        return chart;

    }

    /**
     * Creates a dataset, consisting of two series of monthly data.
     *
     * @return The dataset.
     */
    private static XYDataset createDataset() {

        TimeSeries s1 = new TimeSeries("L&G European Index Trust");
        s1.add(new Month(2, 2001), 181.8);
        s1.add(new Month(3, 2001), 167.3);
        s1.add(new Month(4, 2001), 153.8);
        s1.add(new Month(5, 2001), 167.6);
        s1.add(new Month(6, 2001), 158.8);
        s1.add(new Month(7, 2001), 148.3);
        s1.add(new Month(8, 2001), 153.9);
        s1.add(new Month(9, 2001), 142.7);
        s1.add(new Month(10, 2001), 123.2);
        s1.add(new Month(11, 2001), 131.8);
        s1.add(new Month(12, 2001), 139.6);
        s1.add(new Month(1, 2002), 142.9);
        s1.add(new Month(2, 2002), 138.7);
        s1.add(new Month(3, 2002), 137.3);
        s1.add(new Month(4, 2002), 143.9);
        s1.add(new Month(5, 2002), 139.8);
        s1.add(new Month(6, 2002), 137.0);
        s1.add(new Month(7, 2002), 132.8);

        TimeSeries s2 = new TimeSeries("L&G UK Index Trust");
        s2.add(new Month(2, 2001), 129.6);
        s2.add(new Month(3, 2001), 123.2);
        s2.add(new Month(4, 2001), 117.2);
        s2.add(new Month(5, 2001), 124.1);
        s2.add(new Month(6, 2001), 122.6);
        s2.add(new Month(7, 2001), 119.2);
        s2.add(new Month(8, 2001), 116.5);
        s2.add(new Month(9, 2001), 112.7);
        s2.add(new Month(10, 2001), 101.5);
        s2.add(new Month(11, 2001), 106.1);
        s2.add(new Month(12, 2001), 110.3);
        s2.add(new Month(1, 2002), 111.7);
        s2.add(new Month(2, 2002), 111.0);
        s2.add(new Month(3, 2002), 109.6);
        s2.add(new Month(4, 2002), 113.2);
        s2.add(new Month(5, 2002), 111.6);
        s2.add(new Month(6, 2002), 108.8);
        s2.add(new Month(7, 2002), 101.6);

        TimeSeriesCollection dataset = new TimeSeriesCollection();
        dataset.addSeries(s1);
        dataset.addSeries(s2);

        return dataset;

    }

    /**
     * Creates a panel for the demo (used by SuperDemo.java).
     *
     * @return A panel.
     */
    public static JPanel createDemoPanel() {
        JFreeChart chart = createChart(createDataset());
        ChartPanel panel = new ChartPanel(chart);
        panel.setFillZoomRectangle(true);
        panel.setMouseWheelEnabled(true);
        return panel;
    }

    /**
     * Starting point for the demonstration application.
     *
     * @param args  ignored.
     */
    public static void main(String[] args) {

        TimeSeriesChartDemo1 demo = new TimeSeriesChartDemo1(
                "Time Series Chart Demo 1");
        demo.pack();
        RefineryUtilities.centerFrameOnScreen(demo);
        demo.setVisible(true);

    }

}

Answer 1

You need to extend the Applet class and override the paint(Graphics g) method. the key code is chart.draw( (Graphics2D) g,getBounds()); to used the draw the chart on the Graphics g .

If you are new to Java you may want to take a look at the tutorial

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.text.SimpleDateFormat;

import javax.swing.JApplet;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.DateAxis;
import org.jfree.chart.plot.XYPlot;
import org.jfree.chart.renderer.xy.XYItemRenderer;
import org.jfree.chart.renderer.xy.XYLineAndShapeRenderer;
import org.jfree.data.time.Month;
import org.jfree.data.time.TimeSeries;
import org.jfree.data.time.TimeSeriesCollection;
import org.jfree.data.xy.XYDataset;
import org.jfree.ui.RectangleInsets;

public class AppletDemo extends JApplet {

    @Override
    public void paint(Graphics g) {
        JFreeChart chart = createChart(createDataset());
        chart.draw( (Graphics2D)g,getBounds()); 
    }

    private static JFreeChart createChart(XYDataset dataset) {

        JFreeChart chart = ChartFactory.createTimeSeriesChart(
            "Example Chart",  
            "Date",            
            "Value",   
            dataset,            
            true,               
            true,               
            false              
        );

        chart.setBackgroundPaint(Color.white);

        XYPlot plot = (XYPlot) chart.getPlot();
        plot.setBackgroundPaint(Color.lightGray);
        plot.setDomainGridlinePaint(Color.white);
        plot.setRangeGridlinePaint(Color.white);
        plot.setAxisOffset(new RectangleInsets(5.0, 5.0, 5.0, 5.0));
        plot.setDomainCrosshairVisible(true);
        plot.setRangeCrosshairVisible(true);

        XYItemRenderer r = plot.getRenderer();
        if (r instanceof XYLineAndShapeRenderer) {
            XYLineAndShapeRenderer renderer = (XYLineAndShapeRenderer) r;
            renderer.setBaseShapesVisible(true);
            renderer.setBaseShapesFilled(true);
            renderer.setDrawSeriesLineAsPath(true);
        }

        DateAxis axis = (DateAxis) plot.getDomainAxis();
        axis.setDateFormatOverride(new SimpleDateFormat("MMM-yyyy"));

        return chart;

    }

    private static XYDataset createDataset() {

        TimeSeries s1 = new TimeSeries("Series 1");
        s1.add(new Month(2, 2001), Math.random());
        s1.add(new Month(3, 2001), Math.random());
        s1.add(new Month(4, 2001), Math.random());
        s1.add(new Month(5, 2001), Math.random());


        TimeSeries s2 = new TimeSeries("Series 2");
        s2.add(new Month(2, 2001), Math.random());
        s2.add(new Month(3, 2001), Math.random());
        s2.add(new Month(4, 2001), Math.random());
        s2.add(new Month(5, 2001), Math.random());
        s2.add(new Month(6, 2001), Math.random());


        TimeSeriesCollection dataset = new TimeSeriesCollection();
        dataset.addSeries(s1);
        dataset.addSeries(s2);

        return dataset;

    }
}