java - 如何解决此 iText PDF 错误？

Question

我正在使用 iText PDF 合并两个 pdf 页面(test1.pdf 和 test2.pdf)，并在 test_result.pdf 中获得输出。但输出页面并没有像输入页面那样出来，它被裁剪为实际大小的一半。如何克服这个错误？这是我的代码:

public class MergePDF {
public static void main(String[] args) {
    try {
        List<InputStream> pdfs = new ArrayList<InputStream>();
        pdfs.add(new FileInputStream("test1.pdf"));
        pdfs.add(new FileInputStream("test2.pdf/"));
      //  pdfs.add(new FileInputStream("test_result.pdf/"));
        OutputStream output = new FileOutputStream("/home/ant000112/merge_result.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);
        BaseFont bf = BaseFont.createFont(BaseFont.HELVETICA,BaseFont.CP1257, 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();
        System.out.println("ghghklh");
        try {
            if (outputStream != null)
                outputStream.close();
        } catch (IOException ioe) {
            ioe.printStackTrace();
        }
    }
}

Answer 1

您是否尝试过阅读 iText 网站上的示例？看来你正在以不同的方式做这件事。就像您没有使用 PdfCopy 一样。

/*
 * This class is part of the book "iText in Action - 2nd Edition"
 * written by Bruno Lowagie (ISBN: 9781935182610)
 * For more info, go to: http://itextpdf.com/examples/
 * This example only works with the AGPL version of iText.
 */

package part2.chapter06;

import java.io.FileOutputStream;
import java.io.IOException;
import java.sql.SQLException;

import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.pdf.PdfCopy;
import com.itextpdf.text.pdf.PdfReader;

import part1.chapter02.MovieHistory;
import part1.chapter02.MovieLinks1;

public class Concatenate {

    /** The resulting PDF file. */
    public static final String RESULT
        = "results/part2/chapter06/concatenated.pdf";

    /**
     * Main method.
     * @param    args    no arguments needed
     * @throws DocumentException 
     * @throws IOException
     * @throws SQLException
     */
    public static void main(String[] args)
        throws IOException, DocumentException, SQLException {
        // using previous examples to create PDFs
        MovieLinks1.main(args);
        MovieHistory.main(args);
        String[] files = { MovieLinks1.RESULT, MovieHistory.RESULT };
        // step 1
        Document document = new Document();
        // step 2
        PdfCopy copy = new PdfCopy(document, new FileOutputStream(RESULT));
        // step 3
        document.open();
        // step 4
        PdfReader reader;
        int n;
        // loop over the documents you want to concatenate
        for (int i = 0; i < files.length; i++) {
            reader = new PdfReader(files[i]);
            // loop over the pages in that document
            n = reader.getNumberOfPages();
            for (int page = 0; page < n; ) {
                copy.addPage(copy.getImportedPage(reader, ++page));
            }
            copy.freeReader(reader);
        }
        // step 5
        document.close();
    }
}

http://itextpdf.com/examples/iia.php?id=123

编辑:为了公平起见，我下载了该库并尝试了该示例。它就像一个魅力。