饼图使用 jFreechart 并在 iText 中添加 pdf 图表

在 try {}中发生错误我只想让它工作。配有用于 jfree 和 itext 的 jar。请帮忙 ：(

package com.pieChart.sample;

import java.awt.geom.Rectangle2D;
import java.io.FileOutputStream;

import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PlotOrientation;
import org.jfree.data.category.DefaultCategoryDataset;
import org.jfree.data.general.DefaultPieDataset;

import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.layout.Document;
import com.orsonpdf.DefaultFontMapper;

public class PieChart {
    public static void main(String[] args) {
        writeChartToPDF(generateBarChart(), 500, 400, "C://barchart.pdf");
        writeChartToPDF(generatePieChart(), 500, 400, "C://piechart.pdf");
    }

    public static JFreeChart generatePieChart() {
        DefaultPieDataset dataSet = new DefaultPieDataset();
        dataSet.setValue("China", 19.64);
        dataSet.setValue("India", 17.3);
        dataSet.setValue("United States", 4.54);
        dataSet.setValue("Indonesia", 3.4);
        dataSet.setValue("Brazil", 2.83);
        dataSet.setValue("Pakistan", 2.48);
        dataSet.setValue("Bangladesh", 2.38);

        JFreeChart chart = ChartFactory.createPieChart(
                "World Population by countries", dataSet, true, true, false);

        return chart;
    }

    public static JFreeChart generateBarChart() {
        DefaultCategoryDataset dataSet = new DefaultCategoryDataset();
        dataSet.setValue(791, "Population", "1750 AD");
        dataSet.setValue(978, "Population", "1800 AD");
        dataSet.setValue(1262, "Population", "1850 AD");
        dataSet.setValue(1650, "Population", "1900 AD");
        dataSet.setValue(2519, "Population", "1950 AD");
        dataSet.setValue(6070, "Population", "2000 AD");

        JFreeChart chart = ChartFactory.createBarChart(
                "World Population growth", "Year", "Population in millions",
                dataSet, PlotOrientation.VERTICAL, false, true, false);

        return chart;
    }

    public static void writeChartToPDF(JFreeChart chart, int width, int height, String fileName) {
        PdfWriter writer = null;

        Document document = new Document(null);

        try {
            writer = PdfWriter.getInstance(document, new FileOutputStream(
                    fileName));
            document.open();
            PdfContentByte contentByte = writer.getDirectContent();
            PdfTemplate template = contentByte.createTemplate(width, height);
            Graphics2D graphics2d = template.createGraphics(width, height,
                    new DefaultFontMapper());
            Rectangle2D rectangle2d = new Rectangle2D.Double(0, 0, width,
                    height);

            chart.draw(graphics2d, rectangle2d);

            graphics2d.dispose();
            contentByte.addTemplate(template, 0, 0);

        } catch (Exception e) {
            e.printStackTrace();
        }
        document.close();
   }
}

尝试错误{} 1.PdfWriter 2.PdfContentByte 3.PdfTemplate 4.Graphics2D 5.Default 字体映射器 6.Rectangle2D 所有这些错误都说“无法解析”或“无法解析为类型”

线程“main”中的异常 java.lang.Error：未解决的编译问题：PdfWriter 无法解析为一个类型 Document 无法解析为一个类型 Document 无法解析为一个类型 PdfWriter 无法解析 FileOutputStream 无法解析为一个类型 PdfContentByte 无法解析为一个类型 PdfTemplate 无法解析为一个类型 Graphics2D 无法解析为一个类型 DefaultFontMapper 无法解析为一个类型 Rectangle2D 无法解析为一个类型 Rectangle2D 无法解析为一个类型