我有一个PDF（https://www.dropbox.com/s/g2wqm8ipsp8t8l5/GSA%20500%20PDF_v4.pdf?dl=0），我正在尝试查找它是否包含附加到ImageField的图片。为此，我使用PDFDebugger检查了PDF，并可以看到具有类似以下内容的PDF层次结构：/ page / Annots / AP / N / Resources / XObject / FRM / Resources / XObject / lm0以获取图片。我尝试了一些代码，如下所示，但是我无法超越N / Resources，因为从资源开始，它不是COSDictionary。有什么想法吗？
File pdfFile = new File("C:\\Users\\balana.ITGFIRM\\Desktop\\GSA 500 PDF\\GSA 500 PDF_v4.pdf");
String filePath = pdfFile.getParent() + System.getProperty("file.separator");
document = PDDocument.load(pdfFile);
PDDocumentCatalog pdfCatalog = document.getDocumentCatalog();
PDAcroForm acroForm = pdfCatalog.getAcroForm();
List<PDPage> pages = document.getDocumentCatalog().getAllPages();
for (int i = 0; i < pages.size(); i++) {
PDPage page = pages.get(i);
COSBase test = pages.get(i).getCOSObject();
// System.out.println("page: " + i + " base: "+ test);
if (page != null && (i == 2 || i == 3 || i == 4)) {
if (page.getAnnotations() != null) {
if (page.getAnnotations().get(i) != null) {
List<PDAnnotation> annots = page.getAnnotations();
for (int k = 0; k < annots.size(); k++) {
PDAnnotation annot = annots.get(k);
// String annotationName = annot.getAnnotationName();
// System.out.println("annotation name: "+ annotationName);
if (annot == null) {
return;
} else {
PDAppearanceDictionary appear = annot.getAppearance();
if (appear == null) {
return;
} else {
Map<String, PDAppearanceStream> mapAppear = appear.getNormalAppearance();
// System.out.println("Map appear: "+ mapAppear);
if (mapAppear == null) {
return;
} else {
for (Map.Entry<String, PDAppearanceStream> ent : mapAppear.entrySet()) {
PDAppearanceStream pd = ent.getValue();
if (pd == null) {
return;
} else {
PDResources res = pd.getResources();
Map<String, PDXObject> xObjects = res.getXObjects();
if (xObjects == null)
return;
for (Map.Entry<String, PDXObject> e : xObjects.entrySet()) {
PDXObject xObject = e.getValue();
if (xObject instanceof PDXObjectImage) {
PDXObjectImage image = (PDXObjectImage) xObject;
String suffix = image.getSuffix();
System.out.println("suffix: " + suffix);
}
}
}
}
}
}
}
// System.out.println("appear: "+ appear);
// System.out.println("index: " + k + " annot : "+ annot);
// COSBase annotationBase = annot.getDictionary();
// System.out.println("annot base: "+ annotationBase);
// System.out.println("\n\n");
// COSBase apDict = ((COSDictionary)annotationBase).getItem(COSName.AP);
// System.out.println("annot AP: "+ apDict);
// System.out.println("\n\n");
// COSBase nDict = ((COSDictionary)apDict).getItem(COSName.N);
// System.out.println("annot N: "+ nDict);
// System.out.println("\n\n");
// COSBase appearance = annot.getAppearance().getDictionary();
// System.out.println("appearance : "+ appearance);
// System.out.println("\n\n");
// COSBase resources = ((COSDictionary)appearance).getItem(COSName.RESOURCES);
// System.out.println("resources: "+ resources);
// System.out.println("\n\n");
// COSDictionary annotBaseTemp= (COSDictionary) annot.getCOSObject();
// COSBase xObject = ((COSDictionary)annotBaseTemp).getItem(COSName.XOBJECT);
// System.out.println("xObject: "+ xObject);
// System.out.println("contains: "+ contains);
System.out.println("\n\n");
}
if (page.getAnnotations().get(i).getCOSObject() != null) {
COSBase base = page.getAnnotations().get(i).getCOSObject();
if (base != null) {
COSBase apDict = ((COSDictionary) base).getItem(COSName.AP);
if (apDict != null) {
COSBase nDict = ((COSDictionary) apDict).getItem(COSName.N);
if (nDict != null) {
COSBase resourcesDict = nDict.getCOSObject();
// COSBase resourcesDict =
// ((COSDictionary)nDict).getItem(COSName.RESOURCES);
// COSBase xObject =
// ((COSDictionary)resourcesDict).getItem(COSName.XOBJECT);
// COSBase lm0Dict = ((COSDictionary)xObject).getItem(COSName.IM);
System.out.println("Page: " + i + " AP:" + apDict);
System.out.println("\n\n");
System.out.println("Page: " + i + " ndict: " + nDict);
System.out.println("\n\n");
System.out.println("Page: " + i + " resourcesDict: " + resourcesDict);
System.out.println("\n\n");
System.out.println("Page: " + i + " base: " + base);
System.out.println("\n\n");
// System.out.println("xOjbect: "+xObject);
}
}
}
}
}
}
}
}