/*
* 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.markup.repeater.data;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import org.apache.wicket.model.IModel;
/**
* A convenience class to represent an empty data provider.
*
* @author Phil Kulak
* @param <T>
*/
public class EmptyDataProvider<T> implements IDataProvider<T>
{
private static final long serialVersionUID = 1L;
private static EmptyDataProvider<?> INSTANCE = new EmptyDataProvider<Void>();
/**
* @param <T>
* @return the singleton instance of this class
*/
@SuppressWarnings("unchecked")
public static <T> EmptyDataProvider<T> getInstance()
{
return (EmptyDataProvider<T>)INSTANCE;
}
@Override
public Iterator<T> iterator(long first, long count)
{
List<T> list = Collections.emptyList();
return list.iterator();
}
@Override
public long size()
{
return 0;
}
@Override
public IModel<T> model(Object object)
{
return null;
}
}