Some information on the page size : Page Size « PDF « Java Tutorial

1. Java Tutorial
2. PDF
3. Page Size

import com.lowagie.text.pdf.PdfReader;

public class MainClass {

  public static void main(String[] args) throws Exception {
    PdfReader reader = new PdfReader("HelloWorldToRead.pdf");

    System.out.println("Page size p1: " + reader.getPageSize(1));
    System.out.println("Rotation p1: " + reader.getPageRotation(1));
    System.out.println("Page size p3: " + reader.getPageSize(3));
    System.out.println("Rotation p3: " + reader.getPageRotation(3));
    System.out.println("Size with rotation p3: " + reader.getPageSizeWithRotation(3));

  }
}