/*
* Copyright 2006 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code 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. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package com.sun.xml.internal.xsom.impl.util;
import java.util.Iterator;
/**
* {@link Iterator} that works as a filter to another {@link Iterator}.
*
* @author
* Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)
*/
public abstract class FilterIterator implements Iterator {
private final Iterator core;
private Object next;
protected FilterIterator( Iterator core ) {
this.core = core;
}
/**
* Implemented by the derived class to filter objects.
*
* @return true
* to let the iterator return the object to the client.
*/
protected abstract boolean allows( Object o );
public boolean hasNext() {
while(next==null && core.hasNext()) {
// fetch next
Object o = core.next();
if( allows(o) )
next = o;
}
return next!=null;
}
public Object next() {
Object r = next;
next = null;
return r;
}
public void remove() {
throw new UnsupportedOperationException();
}
}
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