org.jpedal.io.filter.Flate Maven / Gradle / Ivy
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/*
* ===========================================
* Java Pdf Extraction Decoding Access Library
* ===========================================
*
* Project Info: http://www.idrsolutions.com
* Help section for developers at http://www.idrsolutions.com/java-pdf-library-support/
*
* (C) Copyright 1997-2013, IDRsolutions and Contributors.
*
* This file is part of JPedal
*
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 2.1 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 library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* ---------------
* Flate.java
* ---------------
*/
package org.jpedal.io.filter;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.Map;
import java.util.zip.Inflater;
import org.jpedal.objects.raw.PdfDictionary;
import org.jpedal.objects.raw.PdfObject;
import org.jpedal.utils.LogWriter;
/**
* flate
*/
public class Flate extends BaseFilter implements PdfFilter {
// default values
private int predictor = 1, colors = 1, bitsPerComponent = 8, columns = 1;
private boolean hasError = false;
public Flate(PdfObject decodeParms) {
super(decodeParms);
if (decodeParms != null) {
int newBitsPerComponent = decodeParms.getInt(PdfDictionary.BitsPerComponent);
if (newBitsPerComponent != -1) this.bitsPerComponent = newBitsPerComponent;
int newColors = decodeParms.getInt(PdfDictionary.Colors);
if (newColors != -1) this.colors = newColors;
int columnsSet = decodeParms.getInt(PdfDictionary.Columns);
if (columnsSet != -1) this.columns = columnsSet;
this.predictor = decodeParms.getInt(PdfDictionary.Predictor);
}
}
/**
* flate decode - use a byte array stream to decompress data in memory
*
*/
@Override
public byte[] decode(byte[] data) throws Exception {
int bufSize = 512000;
ByteArrayOutputStream bos = null;
boolean failed = true;
int orgSize = data.length;
/**
* decompress byte[]
*/
if (data != null) {
while (failed == true) { // sometimes partly valid so loop to try this
// create an inflater and initialize it
Inflater inf = new Inflater();
inf.setInput(data);
int size = data.length;
bos = new ByteArrayOutputStream(size);
if (size < bufSize) bufSize = size;
byte[] buf = new byte[bufSize];
// int debug = 20;
int count;
try {
while (!inf.finished()) {
count = inf.inflate(buf);
bos.write(buf, 0, count);
if (inf.getRemaining() == 0) break;
}
failed = false;
}
catch (Exception ee) {
if (LogWriter.isOutput()) LogWriter.writeLog("Exception in Flate " + ee);
failed = true;
this.hasError = true;
// retrun on small streams
if (data.length == orgSize && data.length > 10000) {
failed = false;
}
else
if (data.length > 10) {
byte[] newData = new byte[data.length - 1];
System.arraycopy(data, 0, newData, 0, data.length - 1);
data = newData;
}
else failed = false;
}
//Lonzak: fixed memory leak when the inflater is not cleared/end
finally {
inf.end();
inf=null;
}
}
data = bos.toByteArray();
return applyPredictor(this.predictor, data, this.colors, this.bitsPerComponent, this.columns);
}
return data;
}
@Override
public void decode(BufferedInputStream bis, BufferedOutputStream streamCache, String cacheName, Map cachedObjects) throws Exception {
this.bis = bis;
this.streamCache = streamCache;
this.cachedObjects = cachedObjects;
/**
* decompress cached object
*/
if (bis != null) {
InputStream inf = null;
try {
// create a inflater and initialize it Inflater inf=new
// Inflater();
// if((predictor==1) || (predictor==10) )
inf = new java.util.zip.InflaterInputStream(bis);
// else
// inf=new DecodePredictor(null, predictor,params,new
// java.util.zip.InflaterInputStream(bis));
while (true) {
int b = inf.read();
if ((inf.available() == 0) || (b == -1)) break;
streamCache.write(b);
}
if (this.predictor != 1 && this.predictor != 10) {
streamCache.flush();
streamCache.close();
if (cacheName != null) setupCachedObjectForDecoding(cacheName);
}
}
catch (Exception e) {
e.printStackTrace();
if (LogWriter.isOutput()) LogWriter.writeLog("Exception " + e + " accessing Flate filter ");
}
finally {
if (inf != null) {
inf.close();
inf=null;
}
}
}
applyPredictor(this.predictor, null, this.colors, this.bitsPerComponent, this.columns);
}
@Override
public boolean hasError() {
return this.hasError;
}
}