I m 试图使用JFreeChart在RCP应用中使用简单的观点。 我增加了JfreeChart jar档案,作为项目参考图书馆。

由于以下错误,不能形成这种观点:

Could not create the view: Plug-in "ViewJFreeChart" was unable to instantiate class "viewJFreeChart.View".
java.lang.NoClassDefFoundError: org/jfree/data/general/PieDataset
    at java.lang.Class.getDeclaredConstructors0(Native Method)
    at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
    at java.lang.Class.getConstructor0(Unknown Source)
    at java.lang.Class.newInstance0(Unknown Source)
    at java.lang.Class.newInstance(Unknown Source)

......

这是源代码。 java:

package viewJFreeChart;

import java.awt.Font;

import org.eclipse.jface.viewers.IStructuredContentProvider;
import org.eclipse.jface.viewers.ITableLabelProvider;
import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.ui.ISharedImages;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.part.ViewPart;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PiePlot;
import org.jfree.data.general.DefaultPieDataset;
import org.jfree.data.general.PieDataset;
import org.jfree.experimental.chart.swt.ChartComposite;

public class View extends ViewPart {
    public static final String ID = "ViewJFreeChart.view";

    private TableViewer viewer;

    /**
     * This is a callback that will allow us to create the viewer and initialize
     * it.
     */
    public void createPartControl(Composite parent) {

        JFreeChart chart = createChart(createDataset());
        final ChartComposite frame = new ChartComposite(parent, SWT.NONE,
                chart, true);
    }

    /**
     * Passing the focus request to the viewer s control.
     */
    public void setFocus() {
        viewer.getControl().setFocus();
    }

    /**
     * Creates the Dataset for the Pie chart
     */
    private PieDataset createDataset() {
        DefaultPieDataset dataset = new DefaultPieDataset();
        dataset.setValue("One", new Double(43.2));
        dataset.setValue("Two", new Double(10.0));
        dataset.setValue("Three", new Double(27.5));
        dataset.setValue("Four", new Double(17.5));
        dataset.setValue("Five", new Double(11.0));
        dataset.setValue("Six", new Double(19.4));
        return dataset;
    }

    /**
     * Creates the Chart based on a dataset
     */
    private JFreeChart createChart(PieDataset dataset) {

        JFreeChart chart = ChartFactory.createPieChart("Pie Chart Demo 1", // chart
                // title
                dataset, // data
                true, // include legend
                true, false);

        PiePlot plot = (PiePlot) chart.getPlot();
        plot.setSectionOutlinesVisible(false);
        plot.setLabelFont(new Font("SansSerif", Font.PLAIN, 12));
        plot.setNoDataMessage("No data available");
        plot.setCircular(false);
        plot.setLabelGap(0.02);
        return chart;

    }
}