我有800页的PDF文件,我想统计一下这800页中有多少页为空白
You will need to pass it through java.io.RandomAccessFile. It will look similar to this:
int efficientPDFPageCount(File file) {
RandomAccessFile raf = new RandomAccessFile(file, "r");
RandomAccessFileOrArray pdfFile = new RandomAccessFileOrArray(
new RandomAccessSourceFactory().createSource(raf));
PdfReader reader = new PdfReader(pdfFile, new byte[0]);
int pages = reader.getNumberOfPages();
reader.close();
return pages;
}
------ EDIT ------
This is not my code, but I found this on how to detect and delete blank pages.
Here is the link: http://www.rgagnon.com/javadetails/java-detect-and-remove-blank-page-in-pdf.html
I'm not working with Java but in VB.Net, the following code works, I think you just need to get the equivalent methods and convert the code :
Private Sub DeleteEmptyPage()
Dim lstIdxEmptyPage As New List(Of Integer)
For iPage As Integer = 1 To _pdf.GetNumberOfPages
Dim page As PdfPage = _pdf.GetPage(iPage)
Dim pageContent As Byte() = page.GetContentBytes()
If pageContent.Length > 0 Then
Continue For
Else
lstIdxEmptyPage.Add(iPage)
End If
Next
For Each idxPage As Integer In lstIdxEmptyPage
Me._pdf.RemovePage(idxPage)
Next
End Sub
=> _pdf is a iText.Pdfa.PdfADocument object This method will search all pages with empty content (Lenght Bytes = 0). I stored these pages (index) in a list and I will browse this list to remove each page (with it index).
I hope this help.
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