package com.lowagie.tools;import com.lowagie.text.pdf.PdfEncryptor;import com.lowagie.text.pdf.PdfReader;import com.lowagie.text.pdf.PdfWriter;import java.io.FileOutputStream;/** Encrypts a PDF document. It needs iText (http://www.lowagie.com/iText). * @author Paulo Soares (psoares@consiste.pt) */public class encrypt_pdf {        private final static int INPUT_FILE = 0;    private final static int OUTPUT_FILE = 1;    private final static int USER_PASSWORD = 2;    private final static int OWNER_PASSWORD = 3;    private final static int PERMISSIONS = 4;    private final static int STRENGTH = 5;    private final static int permit[] = {        PdfWriter.AllowPrinting,        PdfWriter.AllowModifyContents,        PdfWriter.AllowCopy,        PdfWriter.AllowModifyAnnotations,        PdfWriter.AllowFillIn,        PdfWriter.AllowScreenReaders,        PdfWriter.AllowAssembly,        PdfWriter.AllowDegradedPrinting};    private static void usage() {        System.out.println("usage: input_file output_file user_password owner_password permissions 128|40");        System.out.println("permissions is 8 digit long 0 or 1. Each digit has a particular security function:");        System.out.println();        System.out.println("AllowPrinting");        System.out.println("AllowModifyContents");        System.out.println("AllowCopy");        System.out.println("AllowModifyAnnotations");        System.out.println("AllowFillIn (128 bit only)");        System.out.println("AllowScreenReaders (128 bit only)");        System.out.println("AllowAssembly (128 bit only)");        System.out.println("AllowDegradedPrinting (128 bit only)");        System.out.println("Example permissions to copy and print would be: 10100000");    }        public static void main (String args[]) {        System.out.println("PDF document encryptor");        if (args.length < 6 || args[PERMISSIONS].length() != 8) {            usage();            return;        }        try {            int permissions = 0;            String p = args[PERMISSIONS];            for (int k = 0; k < p.length(); ++k) {                permissions |= (p.charAt(k) == '0' ? 0 : permit[k]);            }            System.out.println("Reading " + args[INPUT_FILE]);            PdfReader reader = new PdfReader(args[INPUT_FILE]);            System.out.println("Writing " + args[OUTPUT_FILE]);            PdfEncryptor.encrypt(reader, new FileOutputStream(args[OUTPUT_FILE]),                args[USER_PASSWORD].getBytes(), args[OWNER_PASSWORD].getBytes(), permissions, args[STRENGTH].equals("128"));            System.out.println("Done.");        }        catch (Exception e) {            e.printStackTrace();        }    }}