/*
* This file is part of the Wayback archival access software
* (http://archive-access.sourceforge.net/projects/wayback/).
*
* Licensed to the Internet Archive (IA) by one or more individual
* contributors.
*
* The IA licenses this file to You 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.archive.wayback.util;
import java.io.IOException;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
*
*
* @author brad
* @version $Date$, $Revision$
*/
public class ObjectFilterIterator<T> implements CloseableIterator<T> {
ObjectFilter<T> filter = null;
Iterator<T> itr = null;
boolean aborted = false;
T cachedNext = null;
public ObjectFilterIterator(Iterator<T> itr,
ObjectFilter<T> filter) {
this.itr = itr;
this.filter = filter;
}
/* (non-Javadoc)
* @see java.util.Iterator#hasNext()
*/
public boolean hasNext() {
if(cachedNext != null) {
return true;
}
if(aborted) {
return false;
}
while(cachedNext == null) {
if(!itr.hasNext()) {
aborted = true;
close();
return false;
}
T maybeNext = itr.next();
int ruling = filter.filterObject(maybeNext);
if(ruling == ObjectFilter.FILTER_ABORT) {
aborted = true;
close();
return false;
} else if(ruling == ObjectFilter.FILTER_INCLUDE) {
cachedNext = maybeNext;
}
}
return true;
}
@SuppressWarnings("unchecked")
public void close() {
if(itr instanceof CloseableIterator) {
CloseableIterator<T> citr =
(CloseableIterator<T>) itr;
try {
citr.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
/* (non-Javadoc)
* @see java.util.Iterator#next()
*/
public T next() {
if(cachedNext == null) {
throw new NoSuchElementException("call hasNext first!");
}
T o = cachedNext;
cachedNext = null;
return o;
}
/* (non-Javadoc)
* @see java.util.Iterator#remove()
*/
public void remove() {
// TODO Auto-generated method stub
}
}