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/*
* 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 io.microsphere.collection;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Objects;
import java.util.function.Consumer;
/**
* Singleton {@link Iterator}
*
* @param the type of elements returned by this iterator
* @author Mercy
* @since 1.0.0
*/
public class SingletonIterator extends ReadOnlyIterator {
private final E element;
private boolean hasNext = true;
public SingletonIterator(E element) {
this.element = element;
}
@Override
public boolean hasNext() {
return hasNext;
}
@Override
public E next() {
if (hasNext) {
hasNext = false;
return element;
}
throw new NoSuchElementException();
}
@Override
public void forEachRemaining(Consumer action) {
Objects.requireNonNull(action);
if (hasNext) {
action.accept(element);
hasNext = false;
}
}
}