image - PDFBox 添加图片时内存不足

Question

我正在使用 PDFBox 从我的 web 应用程序中提取数据并将其放入 PDF 中。我有一种方法可以在每个 PDF 页面上绘制标题。但是，当我向每一页添加图像时，文档内存不足。我想知道是否有人对解决方案有任何想法？这是我的 drawHeader 方法:

公共(public)静态无效drawHeader(PDDocument doc，PDPage页面，PDPageContentStream contentStream，int [] columnWidths，int pageNumber)抛出IOException {

    contentStream.beginText();
    PDFont font = PDType1Font.HELVETICA_BOLD;
    contentStream.setFont(font, 24);
    contentStream.moveTextPositionByAmount(50, 750);
    contentStream.drawString("Producer License Report");
    contentStream.endText();

    contentStream.beginText();
    contentStream.moveTextPositionByAmount(550, 750); 

    contentStream.setFont(PDType1Font.HELVETICA_BOLD, 8);
    contentStream.drawString("Page " + pageNumber);
    contentStream.endText();

    contentStream.drawLine(50, 740, 340, 740);
    contentStream.drawLine(16, 680, 595, 680);

    List<String> headerList = new LinkedList<String>();
    headerList.add("NPN");
    headerList.add("First Name");
    headerList.add("Last Name");
    headerList.add("Suffix");
    headerList.add("License State");
    headerList.add("Resident State");
    headerList.add("License Number");

    contentStream.setFont(PDType1Font.HELVETICA_BOLD, 9);
    float textx = 15;
    float texty = 685;

    InputStream in = new FileInputStream(new File("logo.jpg"));
    PDJpeg img = new PDJpeg(doc, in);
    contentStream.drawImage(img, 375, 720);


    for (int i = 0; i < headerList.size(); i++) {
        String text = headerList.get(i);
        contentStream.beginText();
        contentStream.moveTextPositionByAmount(textx, texty);
        contentStream.drawString(text);
        contentStream.endText();
        textx += (columnWidths[i] * 6.5);
    }
}

Answer 1

我找到了解决办法!您必须在打开 contentStream 之前创建 Image-Object。

例子:

   /* Step 1: Prepare the document.
               */
             doc = new PDDocument();
             PDPage page = new PDPage();
             doc.addPage(page);

             /* Step 2: Prepare the image
              * PDJpeg is the class you use when dealing with jpg images.
              * You will need to mention the jpg file and the document to which it is to be added
              * Note that if you complete these steps after the creating the content stream the PDF
              * file created will show "Out of memory" error.
              */

             PDXObjectImage image = null;
             image = new PDJpeg(doc, new FileInputStream("image.jpg"));
             PDPageContentStream contentStream = new PDPageContentStream(doc,
                    page);
....