PDStream.java
/*
* 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.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.pdfbox.cos.COSArray;
import org.apache.pdfbox.cos.COSBase;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSDocument;
import org.apache.pdfbox.cos.COSInputStream;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.cos.COSNull;
import org.apache.pdfbox.cos.COSStream;
import org.apache.pdfbox.filter.DecodeOptions;
import org.apache.pdfbox.filter.Filter;
import org.apache.pdfbox.filter.FilterFactory;
import org.apache.pdfbox.io.IOUtils;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.common.filespecification.PDFileSpecification;
/**
* A PDStream represents a stream in a PDF document. Streams are tied to a single PDF document.
*
* @author Ben Litchfield
*/
public class PDStream implements COSObjectable
{
private static final Log LOG = LogFactory.getLog(PDStream.class);
private final COSStream stream;
/**
* Creates a new empty PDStream object.
*
* @param document The document that the stream will be part of.
*/
public PDStream(PDDocument document)
{
stream = document.getDocument().createCOSStream();
}
/**
* Creates a new empty PDStream object.
*
* @param document The document that the stream will be part of.
*/
public PDStream(COSDocument document)
{
stream = document.createCOSStream();
}
/**
* Creates a PDStream which wraps the given COSStream.
*
* @param str The stream parameter.
*/
public PDStream(COSStream str)
{
stream = str;
}
/**
* Constructor. Reads all data from the input stream and embeds it into the document. This
* method closes the InputStream.
*
* @param doc The document that will hold the stream.
* @param input The stream parameter.
* @throws IOException If there is an error creating the stream in the document.
*/
public PDStream(PDDocument doc, InputStream input) throws IOException
{
this(doc, input, (COSBase)null);
}
/**
* Constructor. Reads all data from the input stream and embeds it into the document with the
* given filter applied. This method closes the InputStream.
*
* @param doc The document that will hold the stream.
* @param input The stream parameter.
* @param filter Filter to apply to the stream.
* @throws IOException If there is an error creating the stream in the document.
*/
public PDStream(PDDocument doc, InputStream input, COSName filter) throws IOException
{
this(doc, input, (COSBase)filter);
}
/**
* Constructor. Reads all data from the input stream and embeds it into the document with the
* given filters applied. This method closes the InputStream.
*
* @param doc The document that will hold the stream.
* @param input The stream parameter.
* @param filters Filters to apply to the stream.
* @throws IOException If there is an error creating the stream in the document.
*/
public PDStream(PDDocument doc, InputStream input, COSArray filters) throws IOException
{
this(doc, input, (COSBase)filters);
}
/**
* Constructor. Reads all data from the input stream and embeds it into the document with the
* given filters applied, if any. This method closes the InputStream.
*/
private PDStream(PDDocument doc, InputStream input, COSBase filters) throws IOException
{
stream = doc.getDocument().createCOSStream();
try (OutputStream output = stream.createOutputStream(filters))
{
IOUtils.copy(input, output);
}
finally
{
input.close();
}
}
/**
* Get the cos stream associated with this object.
*
* @return The cos object that matches this Java object.
*
*/
@Override
public COSStream getCOSObject()
{
return stream;
}
/**
* This will get a stream that can be written to.
*
* @return An output stream to write data to.
* @throws IOException If an IO error occurs during writing.
*/
public OutputStream createOutputStream() throws IOException
{
return stream.createOutputStream();
}
/**
* This will get a stream that can be written to, with the given filter.
*
* @param filter the filter to be used.
* @return An output stream to write data to.
* @throws IOException If an IO error occurs during writing.
*/
public OutputStream createOutputStream(COSName filter) throws IOException
{
return stream.createOutputStream(filter);
}
/**
* This will get a stream that can be read from.
*
* @return An input stream that can be read from.
* @throws IOException If an IO error occurs during reading.
*/
public COSInputStream createInputStream() throws IOException
{
return stream.createInputStream();
}
public COSInputStream createInputStream(DecodeOptions options) throws IOException
{
return stream.createInputStream(options);
}
/**
* This will get a stream with some filters applied but not others. This is
* useful when doing images, ie filters = [flate,dct], we want to remove
* flate but leave dct
*
* @param stopFilters A list of filters to stop decoding at.
* @return A stream with decoded data.
* @throws IOException If there is an error processing the stream.
*/
public InputStream createInputStream(List<String> stopFilters) throws IOException
{
InputStream is = stream.createRawInputStream();
ByteArrayOutputStream os = new ByteArrayOutputStream();
List<COSName> filters = getFilters();
for (int i = 0; i < filters.size(); i++)
{
COSName nextFilter = filters.get(i);
if ((stopFilters != null) && stopFilters.contains(nextFilter.getName()))
{
break;
}
else
{
Filter filter = FilterFactory.INSTANCE.getFilter(nextFilter);
try
{
filter.decode(is, os, stream, i);
}
finally
{
IOUtils.closeQuietly(is);
}
is = new ByteArrayInputStream(os.toByteArray());
os.reset();
}
}
return is;
}
/**
* This will get the length of the filtered/compressed stream. This is
* readonly in the PD Model and will be managed by this class.
*
* @return The length of the filtered stream.
*/
public int getLength()
{
return stream.getInt(COSName.LENGTH, 0);
}
/**
* This will get the list of filters that are associated with this stream.
*
* @return A (possibly empty) list of all encoding filters to apply to this stream, never null.
*/
public List<COSName> getFilters()
{
COSBase filters = stream.getFilters();
if (filters instanceof COSName)
{
return Collections.singletonList((COSName) filters);
}
else if (filters instanceof COSArray)
{
return (List<COSName>)((COSArray) filters).toList();
}
return Collections.emptyList();
}
/**
* This will set the filters that are part of this stream.
*
* @param filters The filters that are part of this stream.
*/
public void setFilters(List<COSName> filters)
{
stream.setItem(COSName.FILTER, new COSArray(filters));
}
/**
* Get the list of decode parameters. Each entry in the list will refer to
* an entry in the filters list.
*
* @return The list of decode parameters.
* @throws IOException if there is an error retrieving the parameters.
*/
public List<Object> getDecodeParms() throws IOException
{
// See PDF Ref 1.5 implementation note 7, /DP is sometimes used instead.
return internalGetDecodeParams(COSName.DECODE_PARMS, COSName.DP);
}
/**
* Get the list of decode parameters. Each entry in the list will refer to
* an entry in the filters list.
*
* @return The list of decode parameters.
* @throws IOException if there is an error retrieving the parameters.
*/
public List<Object> getFileDecodeParams() throws IOException
{
return internalGetDecodeParams(COSName.F_DECODE_PARMS, null);
}
private List<Object> internalGetDecodeParams(COSName name1, COSName name2) throws IOException
{
COSBase dp = stream.getDictionaryObject(name1, name2);
if (dp instanceof COSDictionary)
{
Map<?, ?> map = COSDictionaryMap.convertBasicTypesToMap((COSDictionary) dp);
return new COSArrayList<>(map, dp, stream, name1);
}
if (dp instanceof COSArray)
{
COSArray array = (COSArray) dp;
List<Object> actuals = new ArrayList<>(array.size());
for (int i = 0; i < array.size(); i++)
{
COSBase base = array.getObject(i);
if (base instanceof COSDictionary)
{
actuals.add(COSDictionaryMap.convertBasicTypesToMap((COSDictionary) base));
}
else
{
LOG.warn("Expected COSDictionary, got " + base + ", ignored");
}
}
return new COSArrayList<>(actuals, array);
}
return null;
}
/**
* This will set the list of decode parameters.
*
* @param decodeParams The list of decode parameters.
*/
public void setDecodeParms(List<?> decodeParams)
{
stream.setItem(COSName.DECODE_PARMS,
COSArrayList.converterToCOSArray(decodeParams));
}
/**
* This will get the file specification for this stream. This is only
* required for external files.
*
* @return The file specification.
* @throws IOException If there is an error creating the file spec.
*/
public PDFileSpecification getFile() throws IOException
{
COSBase f = stream.getDictionaryObject(COSName.F);
return PDFileSpecification.createFS(f);
}
/**
* Set the file specification.
*
* @param f The file specification.
*/
public void setFile(PDFileSpecification f)
{
stream.setItem(COSName.F, f);
}
/**
* This will get the list of filters that are associated with this stream. The list is empty if there are none.
*
* @return A list of all encoding filters to apply to this stream.
*/
public List<String> getFileFilters()
{
COSBase filters = stream.getDictionaryObject(COSName.F_FILTER);
if (filters instanceof COSName)
{
COSName name = (COSName) filters;
return Collections.singletonList(name.getName());
}
else if (filters instanceof COSArray)
{
return ((COSArray) filters).toCOSNameStringList();
}
return Collections.emptyList();
}
/**
* This will set the filters that are part of this stream.
*
* @param filters The filters that are part of this stream.
*/
public void setFileFilters(List<String> filters)
{
COSBase obj = COSArray.ofCOSNames(filters);
stream.setItem(COSName.F_FILTER, obj);
}
/**
* This will set the list of decode params.
*
* @param decodeParams The list of decode params.
*/
public void setFileDecodeParams(List<?> decodeParams)
{
stream.setItem(COSName.F_DECODE_PARMS, COSArrayList.converterToCOSArray(decodeParams));
}
/**
* This will copy the stream into a byte array.
*
* @return The byte array of the filteredStream.
* @throws IOException if an I/O error occurs.
*/
public byte[] toByteArray() throws IOException
{
try (InputStream is = createInputStream())
{
return IOUtils.toByteArray(is);
}
}
/**
* Get the metadata that is part of the document catalog. This will return
* null if there is no meta data for this object.
*
* @return The metadata for this object.
* @throws IllegalStateException if the value of the metadata entry is different from a stream
* or null
*/
public PDMetadata getMetadata()
{
PDMetadata retval = null;
COSBase mdStream = stream.getDictionaryObject(COSName.METADATA);
if (mdStream instanceof COSStream)
{
retval = new PDMetadata((COSStream) mdStream);
}
else if (mdStream instanceof COSNull)
{
// null is authorized
}
else if (mdStream != null)
{
throw new IllegalStateException("Expected a COSStream but was a "
+ mdStream.getClass().getSimpleName());
}
return retval;
}
/**
* Set the metadata for this object. This can be null.
*
* @param meta The meta data for this object.
*/
public void setMetadata(PDMetadata meta)
{
stream.setItem(COSName.METADATA, meta);
}
/**
* Get the decoded stream length.
*
* @return the decoded stream length
*/
public int getDecodedStreamLength()
{
return this.stream.getInt(COSName.DL);
}
/**
* Set the decoded stream length.
*
* @param decodedStreamLength the decoded stream length
*/
public void setDecodedStreamLength(int decodedStreamLength)
{
this.stream.setInt(COSName.DL, decodedStreamLength);
}
}