/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.wicket.core.util.resource.locator.caching;
import org.apache.wicket.util.resource.IResourceStream;
/**
* A singleton reference that is used for resource streams which do not exists. I.e. if there is a
* key in the cache which value is NullResourceStreamReference.INSTANCE then there is no need to
* lookup again for this key anymore.
*/
class NullResourceStreamReference implements IResourceStreamReference
{
final static NullResourceStreamReference INSTANCE = new NullResourceStreamReference();
@Override
public IResourceStream getReference()
{
return null;
}
}