使用Java IText为现有的PDF文档设置新页面大小

Question

I want to set a new page size to my existing PDF document without cropping the contents. I am writing the following code but it just crops my PDF file from the bottom resulting in the loss of content.

The current size is 8.26" X 11.69 " and I need to make it 8.5" X 11".

My code only converts 11.59 to 11. Tried to change 8.26 but its not woking.

Can any one please help? I am using itextpdf-5.5.8 with Java.

import com.itextpdf.text.DocumentException;
import com.itextpdf.text.pdf.GrayColor;
import com.itextpdf.text.pdf.PdfArray;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfDictionary;
import com.itextpdf.text.pdf.PdfName;
import com.itextpdf.text.pdf.PdfNumber;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfRectangle;
import com.itextpdf.text.pdf.PdfStamper;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;



public class PageSize {

    public static final String SRC = "C:/Temp/BC.pdf";
    public static final String DEST = "C:/Temp/BC_New.pdf";

    public static void main(String[] args) throws IOException, DocumentException {
        File file = new File(DEST);
        file.getParentFile().mkdirs();
        new PageSize().manipulatePdf(SRC, DEST);
    }

    public void manipulatePdf(String src, String dest) throws IOException, DocumentException {
        PdfReader reader = new PdfReader(src);
        int n = reader.getNumberOfPages();
        PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(dest));
        // properties
        PdfContentByte over;
        PdfDictionary pageDict;
        PdfRectangle rect = new PdfRectangle(55, 76, 560, 816);
        PdfArray mediabox;
        float llx, lly, ury,llz;
        // loop over every page
        for (int i = 1; i <= n; i++) {
            pageDict = reader.getPageN(i);
            mediabox = pageDict.getAsArray(PdfName.MEDIABOX);
            llx = mediabox.getAsNumber(0).floatValue();
            lly = mediabox.getAsNumber(1).floatValue();
            llz = mediabox.getAsNumber(2).floatValue();
            ury = mediabox.getAsNumber(3).floatValue();
            mediabox.set(1, new PdfNumber((lly + 50)));
            over = stamper.getOverContent(i);
            over.saveState();
                       over.restoreState();
        }



        stamper.close();
        reader.close();
    }
}

UPDATED Here is the code I used to reduce 11.69" to 11". It works fine. But, it won't increase the width 8.26 to 8.5"

import com.itextpdf.text.DocumentException;
import com.itextpdf.text.pdf.GrayColor;
import com.itextpdf.text.pdf.PdfArray;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfDictionary;
import com.itextpdf.text.pdf.PdfName;
import com.itextpdf.text.pdf.PdfNumber;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfRectangle;
import com.itextpdf.text.pdf.PdfStamper;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;



public class PageSize {

    public static final String SRC = "C:/Temp/Test.pdf";
    public static final String DEST = "C:/Temp/BC_New.pdf";

    public static void main(String[] args) throws IOException, DocumentException {
        File file = new File(DEST);
        file.getParentFile().mkdirs();
        new PageSize().manipulatePdf(SRC, DEST);
    }

    public void manipulatePdf(String src, String dest) throws IOException, DocumentException {
        PdfReader reader = new PdfReader(src);
        int n = reader.getNumberOfPages();
        PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(dest));
        // properties
        PdfContentByte over;
        PdfDictionary pageDict;
        PdfArray mediabox;
        float llx, lly, ury,llz;
        // loop over every page
        for (int i = 1; i <= n; i++) {
            pageDict = reader.getPageN(i);
            mediabox = pageDict.getAsArray(PdfName.MEDIABOX);
            llx = mediabox.getAsNumber(0).floatValue();
            lly = mediabox.getAsNumber(1).floatValue();
            ury = mediabox.getAsNumber(3).floatValue();
            mediabox.set(0, new PdfNumber((llx - 17)));
            mediabox.set(1, new PdfNumber((lly + 50)));
            over = stamper.getOverContent(i);
            over.saveState();
                       over.restoreState();
        }



        stamper.close();
        reader.close();
    }
}

SOLVED:

It was a problem with the source file which I was trying to modify. The original source file was a 8.26" X 11.69". A hava program adds a logo to the file and saves it into a new file.

Somehow due to this conversion, the new source file's X-axis got locked and hence my program was not able to modify the x axis.

Hence, I move my program as the first step and it worked. My program first modifies the x and y axis and then passes the file to the other program which does the logo adding stuff.

Thanks Bruno on this. :)

Answer 1

You are changing the page size without changing the content.

If you want to shrink the content, then you need code that is more complex. See Shrinking the contents of a pdf page for an example. There's also an example in the official documentation: How to shrink pages in an existing PDF?

PdfReader reader = new PdfReader(src);
PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(dest));
int n = reader.getNumberOfPages();
PdfDictionary page;
PdfArray crop;
PdfArray media;
for (int p = 1; p <= n; p++) {
    page = reader.getPageN(p);
    media = page.getAsArray(PdfName.CROPBOX);
    if (media == null) {
        media = page.getAsArray(PdfName.MEDIABOX);
    }
    crop = new PdfArray();
    crop.add(new PdfNumber(0));
    crop.add(new PdfNumber(0));
    crop.add(new PdfNumber(media.getAsNumber(2).floatValue() / 2));
    crop.add(new PdfNumber(media.getAsNumber(3).floatValue() / 2));
    page.put(PdfName.MEDIABOX, crop);
    page.put(PdfName.CROPBOX, crop);
    stamper.getUnderContent(p).setLiteral("\nq 0.5 0 0 0.5 0 0 cm\nq\n");
    stamper.getOverContent(p).setLiteral("\nQ\nQ\n");
}
stamper.close();
reader.close();

If you want to enlarge the content, then you can simply change the UserUnit. Changing the UserUnit is also explained in the official documentation: How to rotate and scale pages in an existing PDF?

float factor = 2.5f;
PdfReader reader = new PdfReader(src);
int n = reader.getNumberOfPages();
PdfDictionary page;
for (int p = 1; p <= n; p++) {
    page = reader.getPageN(p);
    if (page.getAsNumber(PdfName.USERUNIT) == null)
        page.put(PdfName.USERUNIT, new PdfNumber(factor));
}
PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(dest));
stamper.close();
reader.close();

This code will scale up the page and its content with a factor 2.5 (because that's what we defined as factor ).

UPDATE

In your update, you have this:

    mediabox = pageDict.getAsArray(PdfName.MEDIABOX);
    llx = mediabox.getAsNumber(0).floatValue();
    lly = mediabox.getAsNumber(1).floatValue();
    ury = mediabox.getAsNumber(3).floatValue();
    mediabox.set(0, new PdfNumber((llx - 17)));
    mediabox.set(1, new PdfNumber((lly + 50)));

By doing so, you add 0.236111 inches in x direction ( llx -17 ) and you subtract 0.69445 inches in y direction. If you say that this changes 11.69 to 11 inch, then I assume that you're talking about the Y direction. If the original width in X direction was originally 8.26, it should be about 8.50.

I don't understand your problem. Of course: my calculations assume that there's no CropBox in your document. Is there a CropBox present?