package it.unimi.dsi.mg4j.document;
/*
* MG4J: Managing Gigabytes for Java
*
* Copyright (C) 2005-2010 Sebastiano Vigna
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation; either version 3 of the License, or (at your option)
* any later version.
*
* This library 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. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*
*/
import it.unimi.dsi.fastutil.objects.Reference2ObjectMap;
import it.unimi.dsi.io.FastBufferedReader;
import it.unimi.dsi.io.WordReader;
import it.unimi.dsi.util.Properties;
import java.io.IOException;
import java.io.InputStream;
import java.io.InterruptedIOException;
import java.io.ObjectInputStream;
import java.io.PipedReader;
import java.io.PipedWriter;
import org.apache.commons.configuration.ConfigurationException;
import org.pdfbox.pdmodel.PDDocument;
import org.pdfbox.util.PDFTextStripper;
/** A factory that converts PDF (Portable Document Format) documents into text.
* Presently this class is very inefficient; it is mainly useful for debugging
* and exemplification purposes.
*/
public class PdfDocumentFactory extends PropertyBasedDocumentFactory {
private static final long serialVersionUID = 1L;
/** Case-insensitive keys for metadata.
*
* @see PropertyBasedDocumentFactory.MetadataKeys
*/
public static enum MetadataKeys {
/** A property specifying that the factory should use the first line of text as a title (not implemented). */
PARSETITLE,
}
/** A PDF text stripper that will be used to extract text from PDF documents. */
private transient PDFTextStripper textStripper;
/** The word reader used for all documents. */
private final WordReader wordReader;
protected boolean parseProperty( final String key, final String[] values, final Reference2ObjectMap<Enum<?>,Object> metadata ) throws ConfigurationException {
if ( sameKey( MetadataKeys.PARSETITLE, key ) ) {
/*metadata.put( PARSE_TITLE, value );
return true;*/
throw new ConfigurationException( "PARSETITLE is not yet implemented" );
}
return super.parseProperty( key, values, metadata );
}
public PdfDocumentFactory() throws IOException {
this.textStripper= new PDFTextStripper();
this.wordReader = new FastBufferedReader();
}
public PdfDocumentFactory( final Properties properties ) throws IOException, ConfigurationException {
super( properties );
this.textStripper= new PDFTextStripper();
this.wordReader = new FastBufferedReader();
}
public PdfDocumentFactory( final Reference2ObjectMap<Enum<?>,Object> defaultMetadata ) throws IOException {
super( defaultMetadata );
this.textStripper= new PDFTextStripper();
this.wordReader = new FastBufferedReader();
}
public PdfDocumentFactory( final String[] property ) throws IOException, ConfigurationException {
super( property );
this.textStripper= new PDFTextStripper();
this.wordReader = new FastBufferedReader();
}
public PdfDocumentFactory copy() {
try {
return new PdfDocumentFactory( defaultMetadata );
}
catch ( IOException e ) {
throw new RuntimeException( e );
}
}
public int numberOfFields() {
return 1;
}
public String fieldName( final int field ) {
ensureFieldIndex( field );
return "text";
}
public int fieldIndex( final String fieldName ) {
return "text".equals( fieldName ) ? 0: -1;
}
public FieldType fieldType( final int field ) {
ensureFieldIndex( field );
return FieldType.TEXT;
}
private void readObject( final ObjectInputStream s ) throws IOException, ClassNotFoundException {
s.defaultReadObject();
textStripper = new PDFTextStripper();
}
public Document getDocument( final InputStream rawContent, final Reference2ObjectMap<Enum<?>,Object> metadata ) {
return new AbstractDocument() {
private PDDocument pdfDocument;
private Thread pipingThread;
private PipedReader pipedReader;
private PipedWriter pipedWriter;
public CharSequence title() {
return (CharSequence)resolve( PropertyBasedDocumentFactory.MetadataKeys.TITLE, metadata );
}
public String toString() {
return title().toString();
}
public CharSequence uri() {
return (CharSequence)resolve( PropertyBasedDocumentFactory.MetadataKeys.URI, metadata );
}
public Object content( final int field ) throws IOException {
ensureFieldIndex( field );
pipedReader = new PipedReader();
pipedWriter = new PipedWriter();
pdfDocument = PDDocument.load( rawContent );
pipedWriter.connect( pipedReader );
pipingThread = new Thread() {
public void run() {
try {
textStripper.writeText( pdfDocument, pipedWriter );
pipedWriter.close();
pipedWriter = null;
}
catch( InterruptedIOException dontCare ) {}
catch ( IOException e ) {
throw new RuntimeException( e );
}
}
};
pipingThread.start();
return pipedReader;
}
public WordReader wordReader( int field ) {
ensureFieldIndex( field );
// TODO: should depend on locale or something.
return wordReader;
}
public void close() throws IOException {
super.close();
if ( pipingThread != null ) {
try {
pipingThread.interrupt();
pipingThread.join();
pipingThread = null;
}
catch ( InterruptedException e ) {
throw new RuntimeException( e );
}
}
if ( pipedReader != null ) {
pipedReader.close();
pipedReader = null;
}
if ( pipedWriter != null ) {
pipedWriter.close();
pipedWriter = null;
}
if ( pdfDocument != null ) {
pdfDocument.close();
pdfDocument = null;
}
}
};
}
}