/*
* @(#)$Id: ChainedIterator.java 3619 2008-03-26 07:23:03Z yui $
*
* Copyright 2006-2008 Makoto YUI
*
* 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.
*
* Contributors:
* Makoto YUI - initial implementation
*/
package xbird.util.iterator;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
*
* <DIV lang="en"></DIV>
* <DIV lang="ja"></DIV>
*
* @author Makoto YUI (yuin405+xbird@gmail.com)
*/
public class ChainedIterator<T> implements Iterator<T> {
private final Iterator<? extends T> _first;
private final Iterator<? extends T> _second;
private boolean _reachedEnd = false;
public ChainedIterator(Iterator<? extends T> first, Iterator<? extends T> second) {
this._first = first;
this._second = second;
}
public Iterator<? extends T> getFirstIterator() {
return _first;
}
public Iterator<? extends T> getSecondIterator() {
return _second;
}
public boolean hasNext() {
if(_reachedEnd) {
return false;
}
if(_first.hasNext()) {
return true;
} else {
final boolean hasmore = _second.hasNext();
if(!hasmore) {
this._reachedEnd = true;
}
return hasmore;
}
}
public T next() {
if(_reachedEnd) {
throw new NoSuchElementException();
}
if(_first.hasNext()) {
return _first.next();
} else if(_second.hasNext()) {
return _second.next();
} else {
_reachedEnd = true;
throw new NoSuchElementException();
}
}
public void remove() {
throw new UnsupportedOperationException();
}
}