/*
* Copyright 2014-2016 the original author or authors.
*
* 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 org.springframework.integration.util;
import java.util.Iterator;
import java.util.function.Function;
/**
* An {@link Iterator} implementation to convert each item from the target
* {@link #iterator} to a new object applying the {@link #function} on {@link #next()}.
*
* @author Artem Bilan
* @since 4.1
*/
public final class FunctionIterator<T, V> implements Iterator<V> {
private final Iterator<T> iterator;
private final Function<? super T, ? extends V> function;
public FunctionIterator(Iterable<T> iterable, Function<? super T, ? extends V> function) {
this(iterable.iterator(), function);
}
public FunctionIterator(Iterator<T> newIterator, Function<? super T, ? extends V> function) {
this.iterator = newIterator;
this.function = function;
}
@Override
public void remove() {
throw new UnsupportedOperationException("Cannot remove from a collect iterator");
}
@Override
public boolean hasNext() {
return this.iterator.hasNext();
}
@Override
public V next() {
return this.function.apply(this.iterator.next());
}
}