使用iText将外部图像添加到PDF [英] Adding external images to PDF using iText

问题描述

我无法弄清楚如何使用iText将外部图像（由URL引用）添加到PDF。这种事情有可能吗？

I'm having trouble figuring out how to add an external image (referenced by a URL) to a PDF using iText. Is this kind of thing possible?

7.1.5中的PDF规范说你应该能够通过URL使用URL规范来引用PDF。这就是我到目前为止所做的：

The PDF spec in 7.1.5 says you should be able to reference a PDF via a URL by using a URL specification. This is what I've got so far:

PdfFileSpecification pdfSpec = 
    PdfFileSpecification.url(writer, "http://www.someurl.com/test.jpg");

StringBufferInputStream sbis = new StringBufferInputStream("");   
PdfStream dict = new PdfStream(sbis, writer);
dict.put(PdfName.FILTER, PdfName.DCTDECODE)
dict.put(PdfName.TYPE, PdfName.XOBJECT);
dict.put(PdfName.SUBTYPE, PdfName.IMAGE);
dict.put(PdfName.WIDTH, new PdfNumber(100));
dict.put(PdfName.HEIGHT, new PdfNumber(100));
dict.put(PdfName.BITSPERCOMPONENT, new PdfNumber(8));
dict.put(PdfName.LENGTH, new PdfNumber(0));
dict.put(PdfName.F, pdfSpec);

PdfIndirectObject img = writer.addToBody(dict);

我知道我仍然需要确保添加色彩空间和东西，但我主要担心的是现在实际上是将这个图像放入文档的正文中。我无法弄清楚如何做到这一点......似乎我无法获得对PdfPage或资源字典或任何东西的引用。这是否可以使用iText？

I know I still need to make sure the color space is added and stuff, but my main concern right now is actually getting this image into the body of the document. I can't figure out how to do this... it seems I can't get a reference to a PdfPage or the resources dictionary or anything. Is this possible using iText?

作为附注，如果我在视图试图加载时会出现安全警告，则此练习无效图片。有谁知道是否是这种情况？

As a side note, this exercise is useless if I'm going to be presented with a security warning when the view tries to go load the image. Does anyone know if that is the case?

推荐答案

PDF规范中描述了外部内容，但实际上几乎没有PDF处理器支持他们。到目前为止，Acrobat 9已经支持它，但我对此功能非常谨慎：您的客户或用户可能无法看到引用的内容。

External content is described in the PDF spec, but almost no PDF processor does actually support them. By now Acrobat 9 has support for it, but I would be very cautious with that feature: Your clients or users may not be able to see the referenced content.

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