/*
* 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.pdmodel.common;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.SequenceInputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Vector;
import org.apache.pdfbox.cos.COSArray;
import org.apache.pdfbox.cos.COSBase;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.cos.COSStream;
import org.apache.pdfbox.cos.ICOSVisitor;
import org.apache.pdfbox.pdfparser.PDFStreamParser;
/**
* This will take an array of streams and sequence them together.
*
* @author <a href="mailto:ben@benlitchfield.com">Ben Litchfield</a>
* @version $Revision: 1.10 $
*/
public class COSStreamArray extends COSStream
{
private COSArray streams;
/**
* The first stream will be used to delegate some of the methods for this
* class.
*/
private COSStream firstStream;
/**
* Constructor.
*
* @param array The array of COSStreams to concatenate together.
*/
public COSStreamArray( COSArray array )
{
super( new COSDictionary() );
streams = array;
if( array.size() > 0 )
{
firstStream = (COSStream)array.getObject( 0 );
}
}
/**
* This will get a stream (or the reference to a stream) from the array.
*
* @param index The index of the requested stream
* @return The stream object or a reference to a stream
*/
public COSBase get( int index )
{
return streams.get( index );
}
/**
* This will get the number of streams in the array.
*
* @return the number of streams
*/
public int getStreamCount()
{
return streams.size();
}
/**
* This will get an object from this streams dictionary.
*
* @param key The key to the object.
*
* @return The dictionary object with the key or null if one does not exist.
*/
public COSBase getItem( COSName key )
{
return firstStream.getItem( key );
}
/**
* This will get an object from this streams dictionary and dereference it
* if necessary.
*
* @param key The key to the object.
*
* @return The dictionary object with the key or null if one does not exist.
*/
public COSBase getDictionaryObject( COSName key )
{
return firstStream.getDictionaryObject( key );
}
/**
* {@inheritDoc}
*/
public String toString()
{
return "COSStream{}";
}
/**
* This will get all the tokens in the stream.
*
* @return All of the tokens in the stream.
*
* @throws IOException If there is an error parsing the stream.
*/
public List<Object> getStreamTokens() throws IOException
{
List<Object> retval = null;
if( streams.size() > 0 )
{
PDFStreamParser parser = new PDFStreamParser( this );
parser.parse();
retval = parser.getTokens();
}
else
{
retval = new ArrayList<Object>();
}
return retval;
}
/**
* This will get the dictionary that is associated with this stream.
*
* @return the object that is associated with this stream.
*/
public COSDictionary getDictionary()
{
return firstStream;
}
/**
* This will get the stream with all of the filters applied.
*
* @return the bytes of the physical (endoced) stream
*
* @throws IOException when encoding/decoding causes an exception
*/
public InputStream getFilteredStream() throws IOException
{
throw new IOException( "Error: Not allowed to get filtered stream from array of streams." );
}
/**
* This will get the logical content stream with none of the filters.
*
* @return the bytes of the logical (decoded) stream
*
* @throws IOException when encoding/decoding causes an exception
*/
public InputStream getUnfilteredStream() throws IOException
{
Vector<InputStream> inputStreams = new Vector<InputStream>();
byte[] inbetweenStreamBytes = "\n".getBytes("ISO-8859-1");
for( int i=0;i<streams.size(); i++ )
{
COSStream stream = (COSStream)streams.getObject( i );
inputStreams.add( stream.getUnfilteredStream() );
//handle the case where there is no whitespace in the
//between streams in the contents array, without this
//it is possible that two operators will get concatenated
//together
inputStreams.add( new ByteArrayInputStream( inbetweenStreamBytes ) );
}
return new SequenceInputStream( inputStreams.elements() );
}
/**
* visitor pattern double dispatch method.
*
* @param visitor The object to notify when visiting this object.
* @return any object, depending on the visitor implementation, or null
* @throws IOException if the output could not be written
*/
public Object accept(ICOSVisitor visitor) throws IOException
{
return streams.accept( visitor );
}
/**
* This will return the filters to apply to the byte stream
* the method will return.
* - null if no filters are to be applied
* - a COSName if one filter is to be applied
* - a COSArray containing COSNames if multiple filters are to be applied
*
* @return the COSBase object representing the filters
*/
public COSBase getFilters()
{
return firstStream.getFilters();
}
/**
* This will create a new stream for which filtered byte should be
* written to. You probably don't want this but want to use the
* createUnfilteredStream, which is used to write raw bytes to.
*
* @return A stream that can be written to.
*
* @throws IOException If there is an error creating the stream.
*/
public OutputStream createFilteredStream() throws IOException
{
return firstStream.createFilteredStream();
}
/**
* This will create a new stream for which filtered byte should be
* written to. You probably don't want this but want to use the
* createUnfilteredStream, which is used to write raw bytes to.
*
* @param expectedLength An entry where a length is expected.
*
* @return A stream that can be written to.
*
* @throws IOException If there is an error creating the stream.
*/
public OutputStream createFilteredStream( COSBase expectedLength ) throws IOException
{
return firstStream.createFilteredStream( expectedLength );
}
/**
* set the filters to be applied to the stream.
*
* @param filters The filters to set on this stream.
*
* @throws IOException If there is an error clearing the old filters.
*/
public void setFilters(COSBase filters) throws IOException
{
//should this be allowed? Should this
//propagate to all streams in the array?
firstStream.setFilters( filters );
}
/**
* This will create an output stream that can be written to.
*
* @return An output stream which raw data bytes should be written to.
*
* @throws IOException If there is an error creating the stream.
*/
public OutputStream createUnfilteredStream() throws IOException
{
return firstStream.createUnfilteredStream();
}
/**
* Appends a new stream to the array that represents this object's stream.
*
* @param streamToAppend The stream to append.
*/
public void appendStream(COSStream streamToAppend)
{
streams.add(streamToAppend);
}
/**
* Insert the given stream at the beginning of the existing stream array.
* @param streamToBeInserted
*/
public void insertCOSStream(PDStream streamToBeInserted)
{
COSArray tmp = new COSArray();
tmp.add(streamToBeInserted);
tmp.addAll(streams);
streams.clear();
streams = tmp;
}
}