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Free Java Reporting Library
/*
* JasperReports - Free Java Reporting Library.
* Copyright (C) 2006 Works, Inc. All rights reserved.
* http://www.works.com
* Copyright (C) 2006 - 2019 TIBCO Software Inc. All rights reserved.
* http://www.jaspersoft.com
*
* Unless you have purchased a commercial license agreement from Jaspersoft,
* the following license terms apply:
*
* This program is part of JasperReports.
*
* JasperReports 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.
*
* JasperReports 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 JasperReports. If not, see .
*/
/*
* Licensed to Jaspersoft Corporation under a Contributer Agreement
*/
package net.sf.jasperreports.engine.fill;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
import net.sf.jasperreports.engine.JRRuntimeException;
import net.sf.jasperreports.engine.JRVirtualizable;
/**
* GZips the pages that it doesn't need, but keeps them in memory.
*
* @author John Bindel
*/
public class JRGzipVirtualizer extends JRAbstractLRUVirtualizer
{
public static final String EXCEPTION_MESSAGE_KEY_NO_DATA_FOUND = "fill.virtualizer.no.data.found";
private final Map zippedData;
/**
* @param maxSize
* the maximum size (in JRVirtualizable objects) of the paged in
* cache.
*/
public JRGzipVirtualizer(int maxSize) {
super(maxSize);
this.zippedData = Collections.synchronizedMap(new HashMap());
}
@Override
protected void dispose(String virtualId) {
zippedData.remove(virtualId);
}
@Override
protected void pageOut(JRVirtualizable o) throws IOException {
if (!zippedData.containsKey(o.getUID())) {
GZIPOutputStream gos = null;
try {
ByteArrayOutputStream baos = new ByteArrayOutputStream(3000);
gos = new GZIPOutputStream(baos);
writeData(o, gos);
gos.finish();
gos.flush();
byte[] data = baos.toByteArray();
zippedData.put(o.getUID(), data);
}
finally {
if (gos != null) {
gos.close();
}
}
}
else {
if (!isReadOnly(o)) {
throw new IllegalStateException(
"Cannot virtualize data because the data for object UID \"" + o.getUID()
+ "\" already exists.");
}
}
}
@Override
protected void pageIn(JRVirtualizable o) throws IOException {
GZIPInputStream gis = null;
try {
byte[] data = zippedData.get(o.getUID());
if (data == null) {
throw
new JRRuntimeException(
EXCEPTION_MESSAGE_KEY_NO_DATA_FOUND,
new Object[]{o.getUID()});
}
ByteArrayInputStream bais = new ByteArrayInputStream(data);
gis = new GZIPInputStream(bais);
readData(o, gis);
}
finally {
if (gis != null) {
gis.close();
}
}
if (!isReadOnly(o)) {
// Wait until we know it worked before tossing the data.
zippedData.remove(o.getUID());
}
}
@Override
public void cleanup()
{
zippedData.clear();
reset();
}
}