PDFBox是ASF下一个提供PDF文档操做lib的开源项目。目前PDFBox的最新版本是1.2.1，一下功能主要提供
* PDF to text extraction
* Merge PDF Documents
* PDF Document Encryption/Decryption
* Lucene Search Engine Integration
* Fill in form data FDF and XFDF
* Create a PDF from a text file
* Create images from PDF pages
* Print a PDF
此代码是从PDFBox源码中拷贝出来的示例代码，实现的是提取PDF文件的元数据，不过[color=red]该元数据是经过XMP（XMP是 Adobe 公司的可扩展元数据平台Extensible Metadata Platform 的缩写。它是一种建立、处理和交换元数据的标准格式）加入到PDF文档中的[/color]。
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package org.apache.pdfbox.examples.pdmodel;import org.apache.pdfbox.exceptions.InvalidPasswordException;import org.apache.pdfbox.pdfparser.PDFParser;import org.apache.pdfbox.pdmodel.PDDocument;import org.apache.pdfbox.pdmodel.PDDocumentCatalog;import org.apache.pdfbox.pdmodel.PDDocumentInformation;import org.apache.pdfbox.pdmodel.common.PDMetadata;import java.io.FileInputStream;import java.io.IOException;import java.text.SimpleDateFormat;import java.util.Calendar;/** * This is an example on how to get a documents metadata information. * * Usage: java org.apache.pdfbox.examples.pdmodel.PrintDocumentMetaData <input-pdf> * * @author <a href="mailto:ben@benlitchfield.com">Ben Litchfield</a> * @version $Revision: 1.11 $ */public class PrintDocumentMetaData{ /** * This will print the documents data. * * @param args The command line arguments. * * @throws Exception If there is an error parsing the document. */ public static void main( String[] args ) throws Exception { if( args.length != 1 ) { usage(); } else { PDDocument document = null; FileInputStream file = null; try { file = new FileInputStream( args[0] ); PDFParser parser = new PDFParser( file ); parser.parse(); document = parser.getPDDocument(); if( document.isEncrypted() ) { try { document.decrypt( "" ); } catch( InvalidPasswordException e ) { System.err.println( "Error: Document is encrypted with a password." ); System.exit( 1 ); } } PrintDocumentMetaData meta = new PrintDocumentMetaData(); meta.printMetadata( document ); } finally { if( file != null ) { file.close(); } if( document != null ) { document.close(); } } } } /** * This will print the usage for this document. */ private static void usage() { System.err.println( "Usage: java org.apache.pdfbox.examples.pdmodel.PrintDocumentMetaData <input-pdf>" ); } /** * This will print the documents data to System.out. * * @param document The document to get the metadata from. * * @throws IOException If there is an error getting the page count. */ public void printMetadata( PDDocument document ) throws IOException { PDDocumentInformation info = document.getDocumentInformation(); PDDocumentCatalog cat = document.getDocumentCatalog(); PDMetadata metadata = cat.getMetadata(); System.out.println( "Page Count=" + document.getNumberOfPages() ); System.out.println( "Title=" + info.getTitle() ); System.out.println( "Author=" + info.getAuthor() ); System.out.println( "Subject=" + info.getSubject() ); System.out.println( "Keywords=" + info.getKeywords() ); System.out.println( "Creator=" + info.getCreator() ); System.out.println( "Producer=" + info.getProducer() ); System.out.println( "Creation Date=" + formatDate( info.getCreationDate() ) ); System.out.println( "Modification Date=" + formatDate( info.getModificationDate() ) ); System.out.println( "Trapped=" + info.getTrapped() ); if( metadata != null ) { System.out.println( "Metadata=" + metadata.getInputStreamAsString() ); } } /** * This will format a date object. * * @param date The date to format. * * @return A string representation of the date. */ private String formatDate( Calendar date ) { String retval = null; if( date != null ) { SimpleDateFormat formatter = new SimpleDateFormat(); retval = formatter.format( date.getTime() ); } return retval; }}