com.mchange.v1.util.JoinedIterator Maven / Gradle / Ivy
/*
* Distributed as part of mchange-commons-java 0.2.11
*
* Copyright (C) 2015 Machinery For Change, Inc.
*
* Author: Steve Waldman
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of EITHER:
*
* 1) The GNU Lesser General Public License (LGPL), version 2.1, as
* published by the Free Software Foundation
*
* OR
*
* 2) The Eclipse Public License (EPL), version 1.0
*
* You may choose which license to accept if you wish to redistribute
* or modify this work. You may offer derivatives of this work
* under the license you have chosen, or you may provide the same
* choice of license which you have been offered here.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* You should have received copies of both LGPL v2.1 and EPL v1.0
* along with this software; see the files LICENSE-EPL and LICENSE-LGPL.
* If not, the text of these licenses are currently available at
*
* LGPL v2.1: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* EPL v1.0: http://www.eclipse.org/org/documents/epl-v10.php
*
*/
package com.mchange.v1.util;
import java.util.*;
public class JoinedIterator implements Iterator
{
Iterator[] its;
Iterator removeIterator = null;
boolean permit_removes;
int cur = 0;
public JoinedIterator(Iterator[] its, boolean permit_removes)
{
this.its = its;
this.permit_removes = permit_removes;
}
public boolean hasNext()
{
if (cur == its.length)
return false;
else if (its[ cur ].hasNext())
return true;
else
{
++cur;
return this.hasNext();
}
}
public Object next()
{
if (! this.hasNext())
throw new NoSuchElementException();
removeIterator = its[cur];
return removeIterator.next();
}
public void remove()
{
if (permit_removes)
{
if (removeIterator != null)
{
removeIterator.remove();
removeIterator = null;
}
else
throw new IllegalStateException("next() not called, or element already removed.");
}
else
throw new UnsupportedOperationException();
}
}