/*
* Copyright 2011-2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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 com.amazonaws.codegen.utils;
import java.util.Arrays;
import java.util.Iterator;
import java.util.NoSuchElementException;
public class CompositeIterable<T> implements Iterable<T> {
private Iterable<Iterable<T>> iterables;
public CompositeIterable(Iterable<Iterable<T>> iterables) {
this.iterables = iterables;
}
@SafeVarargs
public CompositeIterable(Iterable<T>... iterables) {
this.iterables = Arrays.asList(iterables);
}
@Override
public Iterator<T> iterator() {
return new CompositeIterator();
}
private class CompositeIterator implements Iterator<T> {
private Iterator<Iterable<T>> iterableIterator = iterables.iterator();
private Iterator<T> currentIterator;
@Override
public boolean hasNext() {
if (currentIterator != null && currentIterator.hasNext()) {
return true;
}
if (iterableIterator.hasNext()) {
currentIterator = iterableIterator.next().iterator();
return hasNext();
}
return false;
}
@Override
public T next() {
if (!hasNext()) {
throw new NoSuchElementException();
}
return currentIterator.next();
}
}
}