net.sf.jasperreports.engine.util.DeduplicableRegistry Maven / Gradle / Ivy
/*
* JasperReports - Free Java Reporting Library.
* Copyright (C) 2001 - 2016 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 .
*/
package net.sf.jasperreports.engine.util;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import net.sf.jasperreports.engine.Deduplicable;
/**
* A registry of deduplicable objects.
*
* @author Lucian Chirita ([email protected])
*/
public class DeduplicableRegistry
{
private static final Log log = LogFactory.getLog(DeduplicableRegistry.class);
protected static class DeduplicableWrapper
{
private final T object;
private final int hash;
public DeduplicableWrapper(T object)
{
this.object = object;
this.hash = object.getHashCode();
}
@Override
public int hashCode()
{
return hash;
}
@SuppressWarnings("unchecked")
@Override
public boolean equals(Object other)
{
return object.isIdentical(((DeduplicableWrapper) other).object);
}
}
protected static class DeduplicableMap
{
private final Map, T> objects = new HashMap, T>();
public T deduplicate(T object)
{
DeduplicableWrapper key = new DeduplicableWrapper(object);
T existing = objects.get(key);
if (existing == null)
{
objects.put(key, object);
existing = object;
if (log.isDebugEnabled())
{
log.debug("Added object " + object);
}
}
else
{
if (log.isDebugEnabled())
{
log.debug("Found existing instance " + existing + " for object " + object);
}
}
return existing;
}
}
private final Map, DeduplicableMap> typesMap
= new HashMap, DeduplicableMap>();
/**
* Search for a duplicate of a given object in the registry, and add the object
* to the registry if no duplicate found.
*
* @param object the object to be searched or added
* @return a duplicate of the object if found, or the passed object if not
*/
public T deduplicate(T object)
{
DeduplicableMap typeMap = typeMap(object);
return typeMap.deduplicate(object);
}
protected DeduplicableMap typeMap(T object)
{
@SuppressWarnings("unchecked")
DeduplicableMap typeMap = (DeduplicableMap) typesMap.get(object.getClass());
if (typeMap == null)
{
typeMap = new DeduplicableMap();
typesMap.put(object.getClass(), typeMap);
}
return typeMap;
}
}