example/src/main/java/com/fr/function/JFreeToChart.java

// 引入JFreeChart图表 
package com.fr.function;

import java.awt.Color;
import java.awt.image.BufferedImage;
import java.text.NumberFormat;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.axis.CategoryAxis;
import org.jfree.chart.axis.CategoryLabelPositions;
import org.jfree.chart.axis.NumberAxis;
import org.jfree.chart.plot.CategoryPlot;
import org.jfree.chart.plot.DatasetRenderingOrder;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.chart.renderer.category.LineAndShapeRenderer;
import org.jfree.chart.title.TextTitle;
import org.jfree.data.DataUtilities;
import org.jfree.data.DefaultKeyedValues;
import org.jfree.data.category.CategoryDataset;
import org.jfree.data.general.DatasetUtilities;
import org.jfree.util.SortOrder;

import com.fr.script.AbstractFunction;

public class JFreeToChart extends AbstractFunction {
    private String x, y;

    public Object run(Object[] args) {
        this.x = args[0].toString();
        this.y = args[1].toString();
        BufferedImage image = createImage(600, 400);
        return image;
    }

    private BufferedImage createImage(int width, int height) {
        CategoryDataset acategorydataset[] = createDatasets();
        JFreeChart jfreechart = createChart(acategorydataset);
        return jfreechart.createBufferedImage(width, height);
    }

    private CategoryDataset[] createDatasets() {
        DefaultKeyedValues defaultkeyedvalues = new DefaultKeyedValues();
        String[] xValue = this.x.split(",");
        String[] yValue = this.y.split(",");
        for (int i = 0; i < xValue.length; i++) {
            defaultkeyedvalues.addValue(xValue[i], Double.valueOf(yValue[i]));
        }
        defaultkeyedvalues.sortByValues(SortOrder.DESCENDING);
        org.jfree.data.KeyedValues keyedvalues = DataUtilities
                .getCumulativePercentages(defaultkeyedvalues);
        CategoryDataset categorydataset = DatasetUtilities
                .createCategoryDataset("Languages", defaultkeyedvalues);
        CategoryDataset categorydataset1 = DatasetUtilities
                .createCategoryDataset("Cumulative", keyedvalues);
        return (new CategoryDataset[] { categorydataset, categorydataset1 });

    }

    private JFreeChart createChart(CategoryDataset acategorydataset[]) {
        JFreeChart jfreechart = ChartFactory.createBarChart(
                "Freshmeat Software Projects", "Language", "Projects",
                acategorydataset[0], PlotOrientation.VERTICAL, true, true,
                false);
        jfreechart.addSubtitle(new TextTitle("By Programming Language"));
        jfreechart.addSubtitle(new TextTitle("As at 5 March 2003"));
        jfreechart.setBackgroundPaint(Color.white);
        CategoryPlot categoryplot = (CategoryPlot) jfreechart.getPlot();
        categoryplot.setBackgroundPaint(Color.lightGray);
        categoryplot.setRangeGridlinePaint(Color.white);
        CategoryAxis categoryaxis = categoryplot.getDomainAxis();
        categoryaxis.setLowerMargin(0.02D);
        categoryaxis.setUpperMargin(0.02D);
        categoryaxis.setCategoryLabelPositions(CategoryLabelPositions.UP_90);
        NumberAxis numberaxis = (NumberAxis) categoryplot.getRangeAxis();
        numberaxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
        LineAndShapeRenderer lineandshaperenderer = new LineAndShapeRenderer();
        NumberAxis numberaxis1 = new NumberAxis("Percent");
        numberaxis1.setNumberFormatOverride(NumberFormat.getPercentInstance());
        categoryplot.setRangeAxis(1, numberaxis1);
        categoryplot.setDataset(1, acategorydataset[1]);
        categoryplot.setRenderer(1, lineandshaperenderer);
        categoryplot.mapDatasetToRangeAxis(1, 1);
        categoryplot.setDatasetRenderingOrder(DatasetRenderingOrder.FORWARD);
        return jfreechart;
    }
}