啊。首先,让我重写一些源代码。
PdfReader pdf = new PdfReader("in.pdf");
PdfStamper stp = new PdfStamper(pdf, new FileOutputStream("c:\\out.pdf"));
PdfWriter writer = stp.getWriter();
Image img = Image.getInstance("image.png");
PdfDictionary pg = pdf.getPageN(1);
PdfDictionary res = pg.getAsDict.get(PdfName.RESOURCES);
PdfDictionary xobj = res.getAsDict(PdfName.XOBJECT);
if (xobj != null) {
for (Iterator<PdfName> it = xobj.getKeys().iterator(); it.hasNext(); ) {
PdfObject obj = xobj.get(it.next());
if (obj.isIndirect()) {
PdfDictionary tg = (PdfDictionary)PdfReader.getPdfObject(obj);
PdfName type = tg.getAsName(PdfName.SUBTYPE));
if (PdfName.IMAGE.equals(type)) {
PdfReader.killIndirect(obj);
Image maskImage = img.getImageMask();
if (maskImage != null)
writer.addDirectImageSimple(maskImage);
writer.addDirectImageSimple(img, (PRIndirectReference)obj);
break;
}
}
}
}
呼。这getAs
函数可以为您节省大量麻烦,并使您的代码更加清晰。
现在。您需要能够区分各种图像。如果您愿意对事物进行硬编码,您可以找出资源名称并按照该路线进行:
String imageResName[] = {"Img1", "Img2" ... };
Image img[] = {Image.getInstance("foo.png"), Image.getInstance("bar.png"), ... };
for (int i = 0; i < imageResName.length; ++i) {
PdfName curKey = new PdfName(imageResName[i]);
PdfIndirectReference ref = xobj.getAsIndirect(curKey);
PdfReader.killIndirect( ref );
Image maskImage = img[i].getImageMask();
if (maskImage != null) {
writer.addDirectImageSimple(maskImage);
}
writer.addDirectImageSimple(img[i], (PRIndirectReference)ref);
}
如果您不愿意使用硬编码的资源名称(并且没有人会责怪您,恰恰相反,特别是当它们出现的顺序(以及末尾的数字)取决于它们在哈希映射中的顺序时...... [颤抖]),您也许可以根据图像的宽度和高度进行区分。
//keep the original for loop, stepping through resource names
if (PdfName.IMAGE.equals(type)) {
float width = tg.getAsNumber(PdfName.WIDTH).floatValue();
float height = tg.getAsNumber(PdfName.HEIGHT).floatValue();
Image img = getImageFromDimensions(width, height);
Image maskImage = img.getImageMask();
...
}