java - 在另一个 PDF 文件的可用空间附加 PDF

Question

Viral Patel's tutorial有关如何合并和拆分 PDF 文件的信息很有用。不幸的是，我需要的不仅仅是合并文件，而是将一个 PDF 附加到另一个 PDF。

我正在生成报告，其中一个组件是使用 JFreeChart 绘制的图表秒。我制作的图表被转换为 PDF 并通过合并代码再次读取。假设我有用于文本和表格 PDF 的 main.pdf 和用于后者的 chart.pdf。

我确定 main.pdf 有一个额外的空间，另一个图形可以放入其中 chart.pdf 我希望后者被缩放并放置在那里而不会在另一个页面中膨胀。

我有下面的代码，但我似乎无法实现它:

• 创建chart.pdf的代码

  import java.awt.Color;
  import java.awt.Graphics2D;
  import java.awt.Paint;
  import java.awt.geom.Rectangle2D;
  import java.io.FileOutputStream;
  
  import org.jfree.chart.ChartFactory;
  import org.jfree.chart.JFreeChart;
  import org.jfree.chart.axis.NumberAxis;
  import org.jfree.chart.plot.CategoryPlot;
  import org.jfree.chart.plot.PlotOrientation;
  import org.jfree.chart.renderer.category.BarRenderer;
  import org.jfree.chart.renderer.category.CategoryItemRenderer;
  import org.jfree.data.category.DefaultCategoryDataset;
  
  import com.lowagie.text.Document;
  import com.lowagie.text.Rectangle;
  import com.lowagie.text.pdf.DefaultFontMapper;
  import com.lowagie.text.pdf.PdfContentByte;
  import com.lowagie.text.pdf.PdfTemplate;
  import com.lowagie.text.pdf.PdfWriter;
  
  public class ChartDemo {
      public static void main(String[] args) {
          writeChartToPDF(generateBarChart(), 500, 400, "D://chart.pdf");
      }
  
      public static void writeChartToPDF(JFreeChart chart, int width, int height,
              String fileName) {
          PdfWriter writer = null;
          Document document = new Document(new Rectangle(width, height));
  
          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();
      }
  
      public static JFreeChart generateBarChart() {
          DefaultCategoryDataset dataSet = new DefaultCategoryDataset();
          dataSet.setValue(100, "Population", "2");
          dataSet.setValue(78, "Population", "4");
          dataSet.setValue(62, "Population", "6");
          dataSet.setValue(50, "Population", "8");
          dataSet.setValue(39, "Population", "10");
  
          JFreeChart chart = ChartFactory.createBarChart("", "Team number",
                  "Solved problems (%)", dataSet, PlotOrientation.VERTICAL,
                  false, true, false);
          chart.setBackgroundPaint(Color.WHITE);
  
          final CategoryPlot plot = chart.getCategoryPlot();
          plot.setBackgroundPaint(Color.WHITE);
          plot.setDomainGridlinePaint(new Color(204, 204, 204));
          plot.setRangeGridlinePaint(new Color(204, 204, 204));
  
          final NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis();
          rangeAxis.setStandardTickUnits(NumberAxis.createIntegerTickUnits());
  
          final BarRenderer renderer1 = (BarRenderer) plot.getRenderer();
          renderer1.setDrawBarOutline(false);
          renderer1.setShadowVisible(false);
          renderer1.setDrawBarOutline(false);
          renderer1.setSeriesPaint(0, Color.gray);
          renderer1.setSeriesPaint(1, Color.RED);
  
          return chart;
      }
  }
  

• 合并代码

  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  
  import com.lowagie.text.Document;
  import com.lowagie.text.pdf.BaseFont;
  import com.lowagie.text.pdf.PdfContentByte;
  import com.lowagie.text.pdf.PdfImportedPage;
  import com.lowagie.text.pdf.PdfReader;
  import com.lowagie.text.pdf.PdfWriter;
  
  public class MergePdf {
  
      public static void main(String[] args) {
          try {
              List<InputStream> pdfs = new ArrayList<InputStream>();
              pdfs.add(new FileInputStream("D:\\main.pdf"));
              pdfs.add(new FileInputStream("D:\\chart.pdf"));
              OutputStream output = new FileOutputStream("D:\\merge.pdf");
              MergePdf.concatPDFs(pdfs, output, true);
          } catch (Exception e) {
              e.printStackTrace();
          }
      }
  
      public static void concatPDFs(List<InputStream> streamOfPDFFiles,
              OutputStream outputStream, boolean paginate) {
  
          Document document = new Document();
          try {
              List<InputStream> pdfs = streamOfPDFFiles;
              List<PdfReader> readers = new ArrayList<PdfReader>();
              int totalPages = 0;
              Iterator<InputStream> iteratorPDFs = pdfs.iterator();
  
              // Create Readers for the pdfs.
              while (iteratorPDFs.hasNext()) {
                  InputStream pdf = iteratorPDFs.next();
                  PdfReader pdfReader = new PdfReader(pdf);
                  readers.add(pdfReader);
                  totalPages += pdfReader.getNumberOfPages();
              }
              // Create a writer for the outputstream
              PdfWriter writer = PdfWriter.getInstance(document, outputStream);
  
              document.open();
              BaseFont bf = BaseFont.createFont(BaseFont.HELVETICA,
                      BaseFont.CP1252, BaseFont.NOT_EMBEDDED);
              PdfContentByte cb = writer.getDirectContent(); // Holds the PDF
              // data
  
              PdfImportedPage page;
              int currentPageNumber = 0;
              int pageOfCurrentReaderPDF = 0;
              Iterator<PdfReader> iteratorPDFReader = readers.iterator();
  
              // Loop through the PDF files and add to the output.
              while (iteratorPDFReader.hasNext()) {
                  PdfReader pdfReader = iteratorPDFReader.next();
  
                  // Create a new page in the target for each source page.
                  while (pageOfCurrentReaderPDF < pdfReader.getNumberOfPages()) {
                      document.newPage();
                      pageOfCurrentReaderPDF++;
                      currentPageNumber++;
                      page = writer.getImportedPage(pdfReader,
                              pageOfCurrentReaderPDF);
                      cb.addTemplate(page, 0, 0);
  
                      // Code for pagination.
                      if (paginate) {
                          cb.beginText();
                          cb.setFontAndSize(bf, 9);
                          cb.showTextAligned(PdfContentByte.ALIGN_CENTER, ""
                                  + currentPageNumber + " of " + totalPages, 520,
                                  5, 0);
                          cb.endText();
                      }
                  }
                  pageOfCurrentReaderPDF = 0;
              }
              outputStream.flush();
              document.close();
              outputStream.close();
          } catch (Exception e) {
              e.printStackTrace();
          } finally {
              if (document.isOpen())
                  document.close();
              try {
                  if (outputStream != null)
                      outputStream.close();
              } catch (IOException ioe) {
                  ioe.printStackTrace();
              }
          }
      }
  }
  

Answer 1

我的回答并没有直接回答你的问题，但它涵盖了你想要的输出——有一个 JFreeChart 图表 within 一个 iText PDF。

我看到了这个关于如何使用 JFreeChart 制作 iText PDF 的惊人的现场教程:WireLust's "Creating an iText pdf with embedded JFreeChart" .请注意，这使用了 servlet，我将其修改为只是一个独立的代码，使用 iText 和 JFreeCharts 来处理。

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
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.chart.title.TextTitle;
import org.jfree.data.xy.XYSeries;
import org.jfree.data.xy.XYSeriesCollection;

import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Phrase;
import com.itextpdf.text.pdf.DefaultFontMapper;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfTemplate;
import com.itextpdf.text.pdf.PdfWriter;

/**
 * Approaching Pi, Inc. http://www.approachingpi.com
 * <p/>
 * User: tcurran Date: Mar 17, 2008 Time: 2:29:43 AM Desc:
 */
public class PdfChartDemo {

    public static void main(String[] args) throws DocumentException {

        try {
            Document doc = new Document(PageSize.A4);
            PdfWriter docWriter = PdfWriter.getInstance(doc,
                    new FileOutputStream("D:/helix-fossil.pdf"));
            doc.open();

            doc.addProducer();
            doc.addCreator("Jay Leno");
            doc.addTitle("jfreechart pdf");
            doc.setPageSize(PageSize.LETTER);

            doc.open();

            // add some text to the document
            doc.add(new Phrase(
                    "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod "
                            + "tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, "
                            + "quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. "
                            + "Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu "
                            + "fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, "
                            + "sunt in culpa qui officia deserunt mollit anim id est laborum."));

            // build up the dataset for the chart
            XYSeriesCollection dataset = new XYSeriesCollection();

            XYSeries series = new XYSeries("XYGraph");
            series.add(1, 1);
            series.add(2, 3);
            series.add(3, 9);
            series.add(4, 11);

            dataset.addSeries(series);

            // set up the chart
            JFreeChart chart = ChartFactory.createXYLineChart(
                    "XY Chart Sample, non default font", // chart title
                    "x-axis", // domain axis label
                    "y-axis", // range axis label
                    dataset, // data
                    PlotOrientation.VERTICAL, // orientation
                    true, // include legend
                    true, // tooltips
                    false // urls
                    );

            // trick to change the default font of the chart
            chart.setTitle(new TextTitle("XY Chart Sample, non default font",
                    new java.awt.Font("Serif", Font.BOLD, 12)));
            chart.setBackgroundPaint(Color.white);
            chart.setBorderPaint(Color.black);
            chart.setBorderStroke(new BasicStroke(1));
            chart.setBorderVisible(true);

            int width = 260;
            int height = 250;

            // get the direct pdf content
            PdfContentByte dc = docWriter.getDirectContent();

            // get a pdf template from the direct content
            PdfTemplate tp = dc.createTemplate(width, height);

            // create an AWT renderer from the pdf template
            Graphics2D g2 = tp.createGraphics(width, height,
                    new DefaultFontMapper());
            Rectangle2D r2D = new Rectangle2D.Double(0, 0, width, height);
            chart.draw(g2, r2D, null);
            g2.dispose();

            // add the rendered pdf template to the direct content
            // you will have to play around with this because the chart is
            // absolutely positioned.
            // 38 is just a typical left margin
            // docWriter.getVerticalPosition(true) will approximate the position
            // that the content above the chart ended
            dc.addTemplate(tp, 38, docWriter.getVerticalPosition(true) - height);

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

    }
}

它将生成与 servlet 版本相同的 PDF 文件。