Java tutorial
package org.mnsoft.pdfocr; import com.lowagie.text.Document; import com.lowagie.text.pdf.PRAcroForm; import com.lowagie.text.pdf.PdfCopy; import com.lowagie.text.pdf.PdfImportedPage; import com.lowagie.text.pdf.PdfReader; import com.lowagie.text.pdf.PdfWriter; import java.io.FileOutputStream; import java.util.Iterator; import java.util.Map; import java.util.StringTokenizer; /** * PDFTrans.java (v1.2), Copyright (C)2002-2004 Sebastien Aperghis-Tramoni * based on the file Encrypt.java (v1.3), Copyright (C)2002 Bruno Lowagie * * This program is a free software available under the GNU * Lesser General Public License. * * This code is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * * History * ------- * v1.3 - 2010.07.01 * - Matthias Nott made some mindboggingly irrelevant modifications * v1.2 - 2004.04.19 * - merged modifications and corrections by Robin Houston * -> added option --encryption-bits * -> added option --print-info * -> reuse document metadata * -> replaced all StringBuffer's with String's * -> added error checking and reporting * * v1.1 - 2002.12.13 * - updated using CopyPdf.java example from Paulo Soares in order * to keep PDF links (but not the bookmarks) during the conversion * -> uses PdfCopy instead of PdfWriter * -> removed the PdfContentBytes and pages rotation stuff * -> uses copyAcroForm() * * v1.0 - 2002.10.06 * - creation of this program */ public class PDFTrans extends java.lang.Object { /** * @param error the warning string */ public static void warning(String warning) { System.err.println("PDFTrans: warning: " + warning); } /** * @param error the error string */ public static void error(String error) { System.err.println("PDFTrans: error: " + error); System.exit(1); } public static void usage() { System.err.print("usage: pdftrans [options] srcfile destfile\n" + "\n" + "metadata options:\n" + " --title <string> sets the title of the document\n" + " --subject <string> sets the subject of the document\n" + " --keywords <string> sets the keywords field of the document\n" + " --creator <string> sets the creator field of the document\n" + " --author <string> sets the author field of the document\n" + " --print-info prints document information before processing\n" + " --print-keywords prints document keywords before processing\n" + "\n" + "protection/encryption options:\n" + " --user-password <string> sets the user password\n" + " --master-password <string> sets the master password\n" + " --encryption-bits <number> number of encryption bits (40 or 128)\n" + " --permissions <list> comma-separated list of the allowed actions\n" + " available actions: print, degraded-print, copy, modify-contents,\n" + " modify-annotations, assembly, fill-in, screen-readers\n"); System.exit(1); } /** * @param args the command line arguments */ @SuppressWarnings({ "deprecation", "rawtypes" }) public static void main(String[] args) { if (args.length < 2) { usage(); } String input_file = null, output_file = null, doc_title = null, doc_subject = null, doc_keywords = null, doc_creator = null, doc_author = null, user_passwd = null, owner_passwd = null; boolean encrypt = false; boolean encryption_bits = PdfWriter.STRENGTH128BITS; int permissions = 0; boolean print_info = false; boolean print_keywords = false; /* * parse options */ for (int i = 0; i < args.length; i++) { if (args[i].equals("--title")) { doc_title = args[++i]; } else if (args[i].equals("--subject")) { doc_subject = args[++i]; } else if (args[i].equals("--keywords")) { doc_keywords = args[++i]; } else if (args[i].equals("--creator")) { doc_creator = args[++i]; } else if (args[i].equals("--author")) { doc_author = args[++i]; } else if (args[i].equals("--print-info")) { print_info = true; } else if (args[i].equals("--print-keywords")) { print_keywords = true; } else if (args[i].equals("--user-password")) { encrypt = true; user_passwd = args[++i]; } else if (args[i].equals("--master-password")) { encrypt = true; owner_passwd = args[++i]; } else if (args[i].equals("--encryption-bits")) { i++; encrypt = true; if (args[i].equals("128")) { encryption_bits = PdfWriter.STRENGTH128BITS; } else if (args[i].equals("40")) { encryption_bits = PdfWriter.STRENGTH40BITS; } else { usage(); } continue; } else if (args[i].equals("--permissions")) { i++; StringTokenizer st = new StringTokenizer(args[i], ","); while (st.hasMoreTokens()) { String s = st.nextToken(); if (s.equals("print")) { permissions |= PdfWriter.AllowPrinting; } else if (s.equals("degraded-print")) { permissions |= PdfWriter.AllowDegradedPrinting; } else if (s.equals("copy")) { permissions |= PdfWriter.AllowCopy; } else if (s.equals("modify-contents")) { permissions |= PdfWriter.AllowModifyContents; } else if (s.equals("modify-annotations")) { permissions |= PdfWriter.AllowModifyAnnotations; } else if (s.equals("assembly")) { permissions |= PdfWriter.AllowAssembly; } else if (s.equals("fill-in")) { permissions |= PdfWriter.AllowFillIn; } else if (s.equals("screen-readers")) { permissions |= PdfWriter.AllowScreenReaders; } else { warning("Unknown permission '" + s + "' ignored"); } } continue; } else if (args[i].startsWith("--")) { error("Unknown option '" + args[i] + "'"); } else if (input_file == null) { input_file = args[i]; } else if (output_file == null) { output_file = args[i]; } else { usage(); } } if (!print_keywords) { if ((input_file == null) || (output_file == null)) { usage(); } if (input_file.equals(output_file)) { error("Input and output files must be different"); } } try { /* * we create a reader for the input file */ if (!print_keywords) { System.out.println("Reading " + input_file + "..."); } PdfReader reader = new PdfReader(input_file); /* * we retrieve the total number of pages */ final int n = reader.getNumberOfPages(); if (!print_keywords) { System.out.println("There are " + n + " pages in the original file."); } /* * get the document information */ final Map info = reader.getInfo(); /* * print the document information if asked to do so */ if (print_info) { System.out.println("Document information:"); final Iterator it = info.entrySet().iterator(); while (it.hasNext()) { final Map.Entry entry = (Map.Entry) it.next(); System.out.println(entry.getKey() + " = \"" + entry.getValue() + "\""); } } if (print_keywords) { String keywords = "" + info.get("Keywords"); if ((null == keywords) || "null".equals(keywords)) { keywords = ""; } System.out.println(keywords); System.exit(0); } /* * if any meta data field is unspecified, * copy the value from the input document */ if (doc_title == null) { doc_title = (String) info.get("Title"); } if (doc_subject == null) { doc_subject = (String) info.get("Subject"); } if (doc_keywords == null) { doc_keywords = (String) info.get("Keywords"); } if (doc_creator == null) { doc_creator = (String) info.get("Creator"); } if (doc_author == null) { doc_author = (String) info.get("Author"); } // null metadata field are simply set to the empty string if (doc_title == null) { doc_title = ""; } if (doc_subject == null) { doc_subject = ""; } if (doc_keywords == null) { doc_keywords = ""; } if (doc_creator == null) { doc_creator = ""; } if (doc_author == null) { doc_author = ""; } /* * step 1: creation of a document-object */ final Document document = new Document(reader.getPageSizeWithRotation(1)); /* * step 2: we create a writer that listens to the document */ final PdfCopy writer = new PdfCopy(document, new FileOutputStream(output_file)); /* * step 3.1: we add the meta data */ document.addTitle(doc_title); document.addSubject(doc_subject); document.addKeywords(doc_keywords); document.addCreator(doc_creator); document.addAuthor(doc_author); /* * step 3.2: we set up the protection and encryption parameters */ if (encrypt) { writer.setEncryption(encryption_bits, user_passwd, owner_passwd, permissions); } /* * step 4: we open the document */ System.out.print("Writing " + output_file + "... "); document.open(); PdfImportedPage page; int i = 0; // step 5: we add content while (i < n) { i++; page = writer.getImportedPage(reader, i); writer.addPage(page); System.out.print("[" + i + "] "); } final PRAcroForm form = reader.getAcroForm(); if (form != null) { writer.copyAcroForm(reader); } System.out.println(); // step 6: we close the document document.close(); } catch (Exception e) { error(e.getClass().getName() + ": " + e.getMessage()); } } }