/***********************************************************************************************************************
* 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.nephele.util;
import java.util.Iterator;
/**
* An auxiliary implementation of an iterator which protects the underlying collection from being modified. As a result,
* calling the remove method on this iterator will result in an {@link UnsupportedOperationException}.
* <p>
* This class is thread-safe.
*
* @param <T>
* the type of the encapsulated iterator
*/
public final class UnmodifiableIterator<T> implements Iterator<T> {
/**
* The encapsulated iterator.
*/
private final Iterator<T> encapsulatedIterator;
/**
* Constructs a new unmodifiable iterator.
*
* @param encapsulatedIterator
* the encapsulated iterator
*/
public UnmodifiableIterator(final Iterator<T> encapsulatedIterator) {
this.encapsulatedIterator = encapsulatedIterator;
}
@Override
public boolean hasNext() {
return this.encapsulatedIterator.hasNext();
}
@Override
public T next() {
return this.encapsulatedIterator.next();
}
@Override
public void remove() {
throw new UnsupportedOperationException("Calling the remove method on this iterator is not allowed");
}
}