Mega Code Archive
An Iterator wrapper for an Object[], allow us to deal with all array like structures in a consistent manner
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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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.
*/
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.lang.reflect.Array;
/**
* <p>
* An Iterator wrapper for an Object[]. This will
* allow us to deal with all array like structures
* in a consistent manner.
* </p>
* <p>
* WARNING : this class's operations are NOT synchronized.
* It is meant to be used in a single thread, newly created
* for each use in the #foreach() directive.
* If this is used or shared, synchronize in the
* next() method.
* </p>
*
* @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
* @author <a href="mailto:geirm@apache.org">Geir Magnusson Jr.</a>
* @version $Id: ArrayIterator.java 463298 2006-10-12 16:10:32Z henning $
*/
public class ArrayIterator implements Iterator
{
/**
* The objects to iterate.
*/
private Object array;
/**
* The current position and size in the array.
*/
private int pos;
private int size;
/**
* Creates a new iterator instance for the specified array.
*
* @param array The array for which an iterator is desired.
*/
public ArrayIterator(Object array)
{
/*
* if this isn't an array, then throw. Note that this is
* for internal use - so this should never happen - if it does
* we screwed up.
*/
if ( !array.getClass().isArray() )
{
throw new IllegalArgumentException(
"Programmer error : internal ArrayIterator invoked w/o array");
}
this.array = array;
pos = 0;
size = Array.getLength( this.array );
}
/**
* Move to next element in the array.
*
* @return The next object in the array.
*/
public Object next()
{
if (pos < size )
return Array.get( array, pos++);
/*
* we screwed up...
*/
throw new NoSuchElementException("No more elements: " + pos +
" / " + size);
}
/**
* Check to see if there is another element in the array.
*
* @return Whether there is another element.
*/
public boolean hasNext()
{
return (pos < size );
}
/**
* No op--merely added to satify the <code>Iterator</code> interface.
*/
public void remove()
{
throw new UnsupportedOperationException();
}
}
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