如何从iText中的PDF中删除空白页面

Question

我想从使用Java中的iText库生成的PDF中删除空白页面.

我该怎么做？

Answer 1

C#(按照kalyan的要求)

public static void removeBlankPdfPages(string pdfSourceFile, string pdfDestinationFile, bool debug) {

// step 0: set minimum page size
const int blankPdfsize = 20;

// step 1: create new reader
var r = new PdfReader(pdfSourceFile);
var raf = new RandomAccessFileOrArray(pdfSourceFile);
var document = new Document(r.GetPageSizeWithRotation(1));

// step 2: create a writer that listens to the document
var writer = new PdfCopy(document, new FileStream(pdfDestinationFile, FileMode.Create));

// step 3: we open the document
document.Open();

// step 4: we add content
PdfImportedPage page = null;

//loop through each page and if the bs is larger than 20 than we know it is not blank.
//if it is less than 20 than we don't include that blank page.
for (var i=1 ; i <= r.NumberOfPages; i++)
{
    //get the page content
    byte[] bContent = r.GetPageContent(i, raf);
    var bs = new MemoryStream();

    //write the content to an output stream
    bs.Write(bContent, 0, bContent.Length);
    Console.WriteLine("page content length of page {0} = {1}", i, bs.Length);

    //add the page to the new pdf
    if (bs.Length > blankPdfsize)
    {
        page = writer.GetImportedPage(r, i);
        writer.AddPage(page);
    }
    bs.Close();
}
//close everything
document.Close();
writer.Close();
raf.Close();
r.Close();}