I try to add the footer as the first post, but there is no affection.
and I look at the example in iText in Action.
There is in_action.chapter18.HelloWorldStream class
so I follow it, and modify the code like above, it also no affection
Joined: Mar 22, 2005
I don't think you can use HeaderFooter when altering an existing document - you need to work with lower-level classes. I also think that PdfStamper is a better choice than PdfCopy.
Here's an example that adds text to an existing document: http://1t3xt.info/examples/browse/?page=example&id=24 (that would be in the "getOverContent" part). Instead of setTextMatrix and showText you may want to use "over.showTextAligned(PdfContentByte.ALIGN_RIGHT, text, x, y, 0)" with suitable values for x and y (which will depend on the page size).