[PDFBOX-4035] Render PDF to image may be cause OOM

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 2.0.7
• Component/s: Rendering
• Environment: Mac os 10.13.2 ; Ubuntu 16.04.2 LTS
• Flags: Important
• Assignee: Unassigned
• Reporter: Liu KeFeng
• Created: 15/Dec/17 02:42
• Updated: 03/Jan/18 17:14
• Resolved: 03/Jan/18 17:14

Description

My project need render every pdf page to image, and use scale.
This is my code:

  public void pdfToImage(String uuid, String date, String pdfFileLocation, String saveParentFolder) {
    File pdfFile = new File(pdfFileLocation);
    try (PDDocument doc = PDDocument.load(pdfFile, MemoryUsageSetting.setupTempFileOnly())) {
      PDFRenderer renderer = new PDFRenderer(doc);
      int page = doc.getNumberOfPages();
      String imagePath = saveParentFolder + "/" + date + "/" + uuid + "/";
      File folder = new File(imagePath);
      if (!folder.exists() && !folder.mkdirs()) {
        throw new IllegalStateException("create directory " + imagePath + " error");
      }
      for (int i = 0; i < page; i++) {
        int subPage = i;
        Future<Void> future = callerRunExecutor.submit(() -> {
          BufferedImage image = renderer.renderImageWithDPI(subPage, 220);
          String imageLocation = imagePath + (subPage + 1) + appProperties.folderPath.previewImageSuffix;
          writeImage(image, imageLocation);
          return null;
        });
        try {
          future.get(5L, TimeUnit.MINUTES);
        } catch (InterruptedException | ExecutionException | TimeoutException e) {
          LOGGER.warn("generate " + pdfFileLocation + " page of  " + subPage + " preview image error.", e);
        }
      }
    } catch (IOException e) {
      throw new ApiException(GatewayError.INTERNAL_ERROR, e);
    }
  }

This code maybe cause OOM. The PDFBox class is DCTFilter, source code:

DataBufferByte dataBuffer = (DataBufferByte)raster.getDataBuffer();

The pdf only have one page, the page only have one image, the image size: 13653 * 18000,
When rendering the image, trigger the user code, the user to choose whether to render, how to render.