freemarker.template.utility.Collections12 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.io.Serializable;
import java.util.AbstractList;
import java.util.AbstractMap;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* Implementation of missing JDK 1.3 collection features for JDK 1.2
* @author Attila Szegedi
* @version $Id: Collections12.java,v 1.2 2004/11/27 14:49:57 ddekany Exp $
*/
public class Collections12
{
public static final Map EMPTY_MAP = new EmptyMap();
private Collections12()
{
}
private static final class EmptyMap
extends AbstractMap
implements Serializable
{
public int size()
{
return 0;
}
public boolean isEmpty()
{
return true;
}
public boolean containsKey(Object key)
{
return false;
}
public boolean containsValue(Object value)
{
return false;
}
public Object get(Object key)
{
return null;
}
public Set keySet()
{
return Collections.EMPTY_SET;
}
public Collection values()
{
return Collections.EMPTY_SET;
}
public Set entrySet()
{
return Collections.EMPTY_SET;
}
public boolean equals(Object o)
{
return (o instanceof Map) && ((Map) o).size() == 0;
}
public int hashCode()
{
return 0;
}
}
public static Map singletonMap(Object key, Object value)
{
return new SingletonMap(key, value);
}
private static class SingletonMap
extends AbstractMap
implements Serializable
{
private final Object k, v;
SingletonMap(Object key, Object value)
{
k = key;
v = value;
}
public int size()
{
return 1;
}
public boolean isEmpty()
{
return false;
}
public boolean containsKey(Object key)
{
return eq(key, k);
}
public boolean containsValue(Object value)
{
return eq(value, v);
}
public Object get(Object key)
{
return (eq(key, k) ? v : null);
}
private transient Set keySet = null;
private transient Set entrySet = null;
private transient Collection values = null;
public Set keySet()
{
if (keySet == null)
keySet = Collections.singleton(k);
return keySet;
}
public Set entrySet()
{
if (entrySet == null)
entrySet = Collections.singleton(new ImmutableEntry(k, v));
return entrySet;
}
public Collection values()
{
if (values == null)
values = Collections.singleton(v);
return values;
}
private static class ImmutableEntry implements Map.Entry
{
final Object k;
final Object v;
ImmutableEntry(Object key, Object value)
{
k = key;
v = value;
}
public Object getKey()
{
return k;
}
public Object getValue()
{
return v;
}
public Object setValue(Object value)
{
throw new UnsupportedOperationException();
}
public boolean equals(Object o)
{
if (!(o instanceof Map.Entry))
return false;
Map.Entry e = (Map.Entry) o;
return eq(e.getKey(), k) && eq(e.getValue(), v);
}
public int hashCode()
{
return (
(k == null ? 0 : k.hashCode())
^ (v == null ? 0 : v.hashCode()));
}
public String toString()
{
return k + "=" + v;
}
}
}
public static List singletonList(Object o)
{
return new SingletonList(o);
}
private static class SingletonList
extends AbstractList
implements Serializable
{
private final Object element;
SingletonList(Object obj)
{
element = obj;
}
public int size()
{
return 1;
}
public boolean contains(Object obj)
{
return eq(obj, element);
}
public Object get(int index)
{
if (index != 0)
throw new IndexOutOfBoundsException(
"Index: " + index + ", Size: 1");
return element;
}
}
private static boolean eq(Object o1, Object o2)
{
return (o1 == null ? o2 == null : o1.equals(o2));
}
}