合并文件时出现错误：期望行，但是遇到了文件结尾。

Question

我将使用PdfBox for android来向PDF文件追加数据。 要追加的数据

public byte [] prerparePdfToAppend() {

    final PDDocument document = new PDDocument();
    final PDPage sourcePage = new PDPage();
    document.addPage(sourcePage);

    PDPageContentStream contentStream = new PDPageContentStream(document, sourcePage);
    contentStream.beginText();
    contentStream.setFont(PDType1Font.COURIER, 12);
    contentStream.showText("Name: " + firstName + " " + lastName);
    contentStream.newLine();
    ...
    contentStream.endText();
    contentStream.close();

    output = new ByteArrayOutputStream();
    document.save(output);
    document.close();
    byte [] bytesToAppend = new byte[output.size()];
    output.write(bytes);
    output.close();

    return bytesToAppend;
}

合并代码（简化版）

public void merge (String assetFileName) {
    byte [] toAppendPdf = prerparePdfToAppend();
    PDFMergerUtility mergerUtility = new PDFMergerUtility();
    mergerUtility.addSource(PDFBoxResourceLoader.getStream(assetFileName));
    mergerUtility.addSource(new ByteArrayInputStream(toAppendPdf));
    mergerUtility.setDestinationStream(destStream);
    mergerUtility.mergeDocuments(); //IOException
}

异常处理

java.io.IOException: Error: End-of-File, expected line
   at org.apache.pdfbox.pdfparser.BaseParser.readLine(BaseParser.java:1419)
   at org.apache.pdfbox.pdfparser.COSParser.parseHeader(COSParser.java:1648)
   at org.apache.pdfbox.pdfparser.COSParser.parsePDFHeader(COSParser.java:1627)
   at org.apache.pdfbox.pdfparser.PDFParser.parse(PDFParser.java:348)
   at org.apache.pdfbox.pdmodel.PDDocument.load(PDDocument.java:888)
   at org.apache.pdfbox.pdmodel.PDDocument.load(PDDocument.java:802)
   at org.apache.pdfbox.multipdf.PDFMergerUtility.mergeDocuments(PDFMergerUtility.java:172)

- royB

---

请将第一个方法更正为实际代码。prerparePdfToAppend()不返回任何内容。它应该返回output.toByteArray()。最后三行是不必要的。您甚至可以通过返回PDDocument并将其附加来进一步缩短代码。 - Tilman Hausherr

Answer 1

我觉得prerparePdfToAppend方法的最后几行看起来很奇怪。但是为什么要让生活变得复杂呢？返回一个PDDocument：

public PDDocument prerparePdfToAppend()
{
    final PDDocument document = new PDDocument();
    final PDPage sourcePage = new PDPage();
    document.addPage(sourcePage);

    PDPageContentStream contentStream = new PDPageContentStream(document, sourcePage);
    contentStream.beginText();
    contentStream.setFont(PDType1Font.COURIER, 12);
    contentStream.showText("Name: " + firstName + " " + lastName);
    contentStream.newLine();
    ...
    contentStream.endText();
    contentStream.close();

    return document;
}

您的合并代码将如下所示：

：

public void merge (String assetFileName)
{
    PDFMergerUtility mergerUtility = new PDFMergerUtility();
    PDDocument srcDoc = PDDocument.load(PDFBoxResourceLoader.getStream(assetFileName));
    PDDocument dstDoc = prerparePdfToAppend();
    mergerUtility.appendDocument(dstDoc, srcDoc);
    dstDoc.save(destStream);
    srcDoc.close();
    dstDoc.close();
}

如果这种方法不起作用，请确保：

PDFBoxResourceLoader.getStream(assetFileName)

这里提到的“流”是指真正的PDF文件流。如果还有问题，请说明新代码中哪一行出现了异常。当然，确保你正在使用最新版本的PDFBox。

- Tilman Hausherr