exec("rundll32 url.dll,FileProtocolHandler c:/Java-Interview.pdf");

package com.mkyong.io;
 
public class AppPDF {
 
  public static void main(String[] args) {
 
    try{
 
	  Process p = Runtime.getRuntime().exec(
"rundll32 url.dll,FileProtocolHandler c:/Java-Interview.pdf");
	  p.waitFor();
 
	  System.out.println("Done");
 
     }catch(Exception ex){
	  ex.printStackTrace();
     }
  }
}