如何将两个PDF文件合并到一个Java中？

我想合并很多PDF文件到一个使用PDFBox ，这就是我所做的：

PDDocument document = new PDDocument(); for (String pdfFile: pdfFiles) { PDDocument part = PDDocument.load(pdfFile); List<PDPage> list = part.getDocumentCatalog().getAllPages(); for (PDPage page: list) { document.addPage(page); } part.close(); } document.save("merged.pdf"); document.close(); 

其中pdfFiles是包含所有PDF文件的ArrayList<String> 。

当我运行上述，我总是得到：

 org.apache.pdfbox.exceptions.COSVisitorException: Bad file descriptor 

难道我做错了什么？ 还有其他方法吗？

Answer 1

为什么不使用pdfbox的PDFMergerUtility ？

 PDFMergerUtility ut = new PDFMergerUtility(); ut.addSource(...); ut.addSource(...); ut.addSource(...); ut.setDestinationFileName(...); ut.mergeDocuments(); 

Answer 2

快速的Googlesearch返回了这个错误： “保存文档和导入的PDF文件时出现错误的文件描述符” 。

它看起来像你需要保持PDF合并打开，直到你已经保存并closures了合并的PDF。

Answer 3

 package article14; import java.io.File; import org.apache.pdfbox.pdmodel.PDDocument; import org.apache.pdfbox.pdmodel.PDPage; import org.apache.pdfbox.util.PDFMergerUtility; public class Pdf { public static void main(String args[]) { new Pdf().createNew(); new Pdf().combine(); } public void combine() { try { PDFMergerUtility mergePdf = new PDFMergerUtility(); String folder ="pdf"; File _folder = new File(folder); File[] filesInFolder; filesInFolder = _folder.listFiles(); for (File string : filesInFolder) { mergePdf.addSource(string); } mergePdf.setDestinationFileName("Combined.pdf"); mergePdf.mergeDocuments(); } catch(Exception e) { } } public void createNew() { PDDocument document = null; try { String filename="test.pdf"; document=new PDDocument(); PDPage blankPage = new PDPage(); document.addPage( blankPage ); document.save( filename ); } catch(Exception e) { } } } 

Answer 4

这是一个可以使用的代码，将四个pdf文件与http://central.maven.org/maven2/com/itextpdf/itextpdf/5.5.0/itextpdf-5.5.0.jar中的; itext.jar合并， http ：//tutorialspointexamples.com/

 import com.itextpdf.text.Document; import com.itextpdf.text.pdf.PdfContentByte; import com.itextpdf.text.pdf.PdfImportedPage; import com.itextpdf.text.pdf.PdfReader; import com.itextpdf.text.pdf.PdfWriter; /** * This class is used to merge two or more * existing pdf file using iText jar. */ public class PDFMerger { static void mergePdfFiles(List<InputStream> inputPdfList, OutputStream outputStream) throws Exception{ //Create document and pdfReader objects. Document document = new Document(); List<PdfReader> readers = new ArrayList<PdfReader>(); int totalPages = 0; //Create pdf Iterator object using inputPdfList. Iterator<InputStream> pdfIterator = inputPdfList.iterator(); // Create reader list for the input pdf files. while (pdfIterator.hasNext()) { InputStream pdf = pdfIterator.next(); PdfReader pdfReader = new PdfReader(pdf); readers.add(pdfReader); totalPages = totalPages + pdfReader.getNumberOfPages(); } // Create writer for the outputStream PdfWriter writer = PdfWriter.getInstance(document, outputStream); //Open document. document.open(); //Contain the pdf data. PdfContentByte pageContentByte = writer.getDirectContent(); PdfImportedPage pdfImportedPage; int currentPdfReaderPage = 1; Iterator<PdfReader> iteratorPDFReader = readers.iterator(); // Iterate and process the reader list. while (iteratorPDFReader.hasNext()) { PdfReader pdfReader = iteratorPDFReader.next(); //Create page and add content. while (currentPdfReaderPage <= pdfReader.getNumberOfPages()) { document.newPage(); pdfImportedPage = writer.getImportedPage( pdfReader,currentPdfReaderPage); pageContentByte.addTemplate(pdfImportedPage, 0, 0); currentPdfReaderPage++; } currentPdfReaderPage = 1; } //Close document and outputStream. outputStream.flush(); document.close(); outputStream.close(); System.out.println("Pdf files merged successfully."); } public static void main(String args[]){ try { //Prepare input pdf file list as list of input stream. List<InputStream> inputPdfList = new ArrayList<InputStream>(); inputPdfList.add(new FileInputStream("..\\pdf\\pdf_1.pdf")); inputPdfList.add(new FileInputStream("..\\pdf\\pdf_2.pdf")); inputPdfList.add(new FileInputStream("..\\pdf\\pdf_3.pdf")); inputPdfList.add(new FileInputStream("..\\pdf\\pdf_4.pdf")); //Prepare output stream for merged pdf file. OutputStream outputStream = new FileOutputStream("..\\pdf\\MergeFile_1234.pdf"); //call method to merge pdf files. mergePdfFiles(inputPdfList, outputStream); } catch (Exception e) { e.printStackTrace(); } } } 

Answer 5

如果你想合并两个文件，其中一个覆盖另一个文件（例如：文档A是一个模板，文档B有你想要放在模板上的文本），这可以工作：

创build“文档”后，你想要写你的模板（templateFile）

  PDDocument watermarkDoc = PDDocument.load(getServletContext() .getRealPath(templateFile)); Overlay overlay = new Overlay(); overlay.overlay(watermarkDoc, doc);