EmptyIterable.java

/*
 * 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.openflamingo.mapreduce.util;

import java.util.Iterator;
import java.util.NoSuchElementException;

/**
 * Helper empty iterable when there are no messages.
 *
 * @param <M> Message data
 */
public class EmptyIterable<M> implements Iterable<M>, Iterator<M> {

	@Override
	public Iterator<M> iterator() {
		return this;
	}

	@Override
	public boolean hasNext() {
		return false;
	}

	@Override
	public M next() {
		throw new NoSuchElementException();
	}

	@Override
	public void remove() {
		throw new UnsupportedOperationException();
	}
}