/**
* Copyright (c) 2003, www.pdfbox.org
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. Neither the name of pdfbox; nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* http://www.pdfbox.org
*
*/
package org.pdfbox.searchengine.lucene;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.Date;
import org.apache.lucene.document.DateField;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.pdfbox.pdmodel.PDDocument;
import org.pdfbox.pdmodel.PDDocumentInformation;
import org.pdfbox.exceptions.CryptographyException;
import org.pdfbox.exceptions.InvalidPasswordException;
import org.pdfbox.util.PDFTextStripper;
/**
* This class is used to create a document for the lucene search engine.
* This should easily plug into the IndexHTML or IndexFiles that comes with
* the lucene project. This class will populate the following fields.
* <table>
* <tr>
* <td>Lucene Field Name</td>
* <td>Description</td>
* </tr>
* <tr>
* <td>path</td>
* <td>File system path if loaded from a file</td>
* </tr>
* <tr>
* <td>url</td>
* <td>URL to PDF document</td>
* </tr>
* <tr>
* <td>contents</td>
* <td>Entire contents of PDF document, indexed but not stored</td>
* </tr>
* <tr>
* <td>summary</td>
* <td>First 500 characters of content</td>
* </tr>
* <tr>
* <td>modified</td>
* <td>The modified date/time according to the url or path</td>
* </tr>
* <tr>
* <td>uid</td>
* <td>A unique identifier for the Lucene document.</td>
* </tr>
* <tr>
* <td>CreationDate</td>
* <td>From PDF meta-data if available</td>
* </tr>
* <tr>
* <td>Creator</td>
* <td>From PDF meta-data if available</td>
* </tr>
* <tr>
* <td>Keywords</td>
* <td>From PDF meta-data if available</td>
* </tr>
* <tr>
* <td>ModificationDate</td>
* <td>From PDF meta-data if available</td>
* </tr>
* <tr>
* <td>Producer</td>
* <td>From PDF meta-data if available</td>
* </tr>
* <tr>
* <td>Subject</td>
* <td>From PDF meta-data if available</td>
* </tr>
* <tr>
* <td>Trapped</td>
* <td>From PDF meta-data if available</td>
* </tr>
* </table>
*
* @author Ben Litchfield
* @version $Revision: 1.18 $
*/
public final class LucenePDFDocument
{
private static final char FILE_SEPARATOR = System.getProperty("file.separator").charAt(0);
/**
* private constructor because there are only static methods.
*/
private LucenePDFDocument()
{
//utility class should not be instantiated
}
/**
* This will get a lucene document from a PDF file.
*
* @param is The stream to read the PDF from.
*
* @return The lucene document.
*
* @throws IOException If there is an error parsing or indexing the document.
*/
public static Document getDocument( InputStream is ) throws IOException
{
Document document = new Document();
addContent( document, is, "<inputstream>" );
return document;
}
/**
* This will get a lucene document from a PDF file.
*
* @param file The file to get the document for.
*
* @return The lucene document.
*
* @throws IOException If there is an error parsing or indexing the document.
*/
public static Document getDocument( File file ) throws IOException
{
Document document = new Document();
// Add the url as a field named "url". Use an UnIndexed field, so
// that the url is just stored with the document, but is not searchable.
document.add( Field.UnIndexed("path", file.getPath() ) );
document.add(Field.UnIndexed("url", file.getPath().replace(FILE_SEPARATOR, '/')));
// Add the last modified date of the file a field named "modified". Use a
// Keyword field, so that it's searchable, but so that no attempt is made
// to tokenize the field into words.
document.add(Field.Keyword("modified", DateField.timeToString( file.lastModified() )));
String uid = file.getPath().replace(FILE_SEPARATOR, '\u0000') + "\u0000" +
DateField.timeToString(file.lastModified() );
// Add the uid as a field, so that index can be incrementally maintained.
// This field is not stored with document, it is indexed, but it is not
// tokenized prior to indexing.
document.add(new Field("uid", uid, false, true, false));
FileInputStream input = null;
try
{
input = new FileInputStream( file );
addContent( document, input, file.getPath() );
}
finally
{
if( input != null )
{
input.close();
}
}
// return the document
return document;
}
/**
* This will get a lucene document from a PDF file.
*
* @param url The file to get the document for.
*
* @return The lucene document.
*
* @throws IOException If there is an error parsing or indexing the document.
*/
public static Document getDocument( URL url ) throws IOException
{
Document document = new Document();
URLConnection connection = url.openConnection();
connection.connect();
// Add the url as a field named "url". Use an UnIndexed field, so
// that the url is just stored with the document, but is not searchable.
document.add( Field.UnIndexed("url", url.toExternalForm() ) );
// Add the last modified date of the file a field named "modified". Use a
// Keyword field, so that it's searchable, but so that no attempt is made
// to tokenize the field into words.
document.add(Field.Keyword("modified", DateField.timeToString( connection.getLastModified())));
String uid = url.toExternalForm().replace(FILE_SEPARATOR, '\u0000') + "\u0000" +
DateField.timeToString( connection.getLastModified() );
// Add the uid as a field, so that index can be incrementally maintained.
// This field is not stored with document, it is indexed, but it is not
// tokenized prior to indexing.
document.add(new Field("uid", uid, false, true, false));
InputStream input = null;
try
{
input = connection.getInputStream();
addContent( document, input,url.toExternalForm() );
}
finally
{
if( input != null )
{
input.close();
}
}
// return the document
return document;
}
/**
* This will add the contents to the lucene document.
*
* @param document The document to add the contents to.
* @param is The stream to get the contents from.
* @param documentLocation The location of the document, used just for debug messages.
*
* @throws IOException If there is an error parsing the document.
*/
private static void addContent( Document document, InputStream is, String documentLocation ) throws IOException
{
PDDocument pdfDocument = null;
try
{
pdfDocument = PDDocument.load( is );
if( pdfDocument.isEncrypted() )
{
//Just try using the default password and move on
pdfDocument.decrypt( "" );
}
//create a writer where to append the text content.
StringWriter writer = new StringWriter();
PDFTextStripper stripper = new PDFTextStripper();
stripper.writeText( pdfDocument, writer );
// Note: the buffer to string operation is costless;
// the char array value of the writer buffer and the content string
// is shared as long as the buffer content is not modified, which will
// not occur here.
String contents = writer.getBuffer().toString();
StringReader reader = new StringReader( contents );
// Add the tag-stripped contents as a Reader-valued Text field so it will
// get tokenized and indexed.
document.add( Field.Text( "contents", reader ) );
PDDocumentInformation info = pdfDocument.getDocumentInformation();
if( info.getAuthor() != null )
{
document.add(Field.Text( "Author", info.getAuthor() ) );
}
if( info.getCreationDate() != null )
{
Date date = info.getCreationDate().getTime();
//for some reason lucene cannot handle dates before the epoch
//and throws a nasty RuntimeException, so we will check and
//verify that this does not happen
if( date.getTime() >= 0 )
{
document.add(Field.Text("CreationDate", DateField.dateToString( date ) ) );
}
}
if( info.getCreator() != null )
{
document.add( Field.Text( "Creator", info.getCreator() ) );
}
if( info.getKeywords() != null )
{
document.add( Field.Text( "Keywords", info.getKeywords() ) );
}
if( info.getModificationDate() != null )
{
Date date = info.getModificationDate().getTime();
//for some reason lucene cannot handle dates before the epoch
//and throws a nasty RuntimeException, so we will check and
//verify that this does not happen
if( date.getTime() >= 0 )
{
document.add(Field.Text("ModificationDate", DateField.dateToString( date ) ) );
}
}
if( info.getProducer() != null )
{
document.add( Field.Text( "Producer", info.getProducer() ) );
}
if( info.getSubject() != null )
{
document.add( Field.Text( "Subject", info.getSubject() ) );
}
if( info.getTitle() != null )
{
document.add( Field.Text( "Title", info.getTitle() ) );
}
if( info.getTrapped() != null )
{
document.add( Field.Text( "Trapped", info.getTrapped() ) );
}
int summarySize = Math.min( contents.length(), 500 );
String summary = contents.substring( 0, summarySize );
// Add the summary as an UnIndexed field, so that it is stored and returned
// with hit documents for display.
document.add( Field.UnIndexed( "summary", summary ) );
}
catch( CryptographyException e )
{
throw new IOException( "Error decrypting document(" + documentLocation + "): " + e );
}
catch( InvalidPasswordException e )
{
//they didn't suppply a password and the default of "" was wrong.
throw new IOException( "Error: The document(" + documentLocation +
") is encrypted and will not be indexed." );
}
finally
{
if( pdfDocument != null )
{
pdfDocument.close();
}
}
}
/**
* This will test creating a document.
*
* usage: java pdfparser.searchengine.lucene.LucenePDFDocument <pdf-document>
*
* @param args command line arguments.
*
* @throws IOException If there is an error.
*/
public static void main( String[] args ) throws IOException
{
if( args.length != 1 )
{
System.err.println( "usage: java org.pdfbox.searchengine.lucene.LucenePDFDocument <pdf-document>" );
System.exit( 1 );
}
System.out.println( "Document=" + getDocument( new File( args[0] ) ) );
}
}