freemarker.template.utility.OptimizerUtil Maven / Gradle / Ivy
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Google App Engine compliant variation of FreeMarker.
FreeMarker is a "template engine"; a generic tool to generate text output based on templates.
/*
* Copyright (c) 2003 The Visigoth Software Society. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowledgement:
* "This product includes software developed by the
* Visigoth Software Society (http://www.visigoths.org/)."
* Alternately, this acknowledgement may appear in the software itself,
* if and wherever such third-party acknowledgements normally appear.
*
* 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
* project contributors may be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [email protected].
*
* 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
* nor may "FreeMarker" or "Visigoth" appear in their names
* without prior written permission of the Visigoth Software Society.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Visigoth Software Society. For more
* information on the Visigoth Software Society, please see
* http://www.visigoths.org/
*/
package freemarker.template.utility;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
/**
* @version $Id: OptimizerUtil.java,v 1.9 2003/02/25 11:52:58 szegedia Exp $
* @author Attila Szegedi
*/
public class OptimizerUtil
{
private static final BigInteger INTEGER_MIN = new BigInteger(Integer.toString(Integer.MIN_VALUE));
private static final BigInteger INTEGER_MAX = new BigInteger(Integer.toString(Integer.MAX_VALUE));
private static final BigInteger LONG_MIN = new BigInteger(Long.toString(Long.MIN_VALUE));
private static final BigInteger LONG_MAX = new BigInteger(Long.toString(Long.MAX_VALUE));
private OptimizerUtil()
{
}
public static List optimizeListStorage(List list)
{
switch(list.size())
{
case 0:
{
return Collections.EMPTY_LIST;
}
case 1:
{
return Collections12.singletonList(list.get(0));
}
default:
{
if(list instanceof ArrayList)
{
((ArrayList)list).trimToSize();
}
return list;
}
}
}
/**
* This is needed to reverse the extreme conversions in arithmetic
* operations so that numbers can be meaningfully used with models that
* don't know what to do with a BigDecimal. Of course, this will make
* impossible for these models (i.e. Jython) to receive a BigDecimal even if
* it was originally placed as such in the data model. However, since
* arithmetic operations aggressively erase the information regarding the
* original number type, we have no other choice to ensure expected operation
* in majority of cases.
*/
public static Number optimizeNumberRepresentation(Number number)
{
if(number instanceof BigDecimal)
{
BigDecimal bd = (BigDecimal) number;
if(bd.scale() == 0)
{
// BigDecimal -> BigInteger
number = bd.unscaledValue();
}
else
{
double d = bd.doubleValue();
if(d != Double.POSITIVE_INFINITY && d != Double.NEGATIVE_INFINITY)
{
// BigDecimal -> Double
return new Double(d);
}
}
}
if(number instanceof BigInteger)
{
BigInteger bi = (BigInteger)number;
if(bi.compareTo(INTEGER_MAX) <= 0 && bi.compareTo(INTEGER_MIN) >= 0)
{
// BigInteger -> Integer
return new Integer(bi.intValue());
}
if(bi.compareTo(LONG_MAX) <= 0 && bi.compareTo(LONG_MIN) >= 0)
{
// BigInteger -> Long
return new Long(bi.longValue());
}
}
return number;
}
}