/***********************************************************************************************************************
* Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
*
* Licensed 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 eu.stratosphere.util;
import java.io.IOException;
/**
* A simple iterator interface. The key differences to the {@link java.util.Iterator} are that this
* iterator accepts an object into which it can place the content if the object is mutable, and that
* it consolidates the logic in a single <code>next()</code> function, rather than in two different
* functions such as <code>hasNext()</code> and <code>next()</code>.
*
* @param <E> The element type of the collection iterated over.
*/
public interface MutableObjectIterator<E> {
/**
* Gets the next element from the collection. The contents of that next element is put into the given target object.
*
* @param reuse The target object into which to place next element if E is mutable.
* @return The filled object or <code>null</code> if the iterator is exhausted
*
* @throws IOException Thrown, if a problem occurred in the underlying I/O layer or in the
* serialization / deserialization logic
*/
public E next(E reuse) throws IOException;
}