A GOF Adapter to make instances of old Enumeration interface behave like new Iterator interface
/*
* Copyright (c) Ian F. Darwin, http://www.darwinsys.com/, 1996-2002.
* All rights reserved. Software written by Ian F. Darwin and others.
* $Id: LICENSE,v 1.8 2004/02/09 03:33:38 ian Exp $
*
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* pioneering role in inventing and promulgating (and standardizing) the Java
* language and environment is gratefully acknowledged.
*
* The pioneering role of Dennis Ritchie and Bjarne Stroustrup, of AT&T, for
* inventing predecessor languages C and C++ is also gratefully acknowledged.
*/
import java.util.Enumeration;
import java.util.Iterator;
/**
* A GOF Adapter to make instances of old Enumeration interface behave like new
* Iterator interface, so we only have to deal with one well-defined
* implementation of the Iterator pattern.
*/
public class EnumerationIterator implements Iterator {
/** The Enumeration being delegated to */
private final Enumeration oldEnum;
/**
* Construct an EnumerationIterator from an old-style Enumeration.
*
* @param old
* The Enumeration to be adapted.
*/
public EnumerationIterator(final Enumeration old) {
oldEnum = old;
}
/**
* Fulfuls the general contract of Iterator.hasNext(), that is, return true
* as long as there is at least one more item in the Iterator.
*/
public boolean hasNext() {
return oldEnum.hasMoreElements();
}
/**
* Fulfuls the general contract of Iterator.next(), that is, returns the
* next element in the Iterator.
*/
public Object next() {
return oldEnum.nextElement();
}
/**
* Remove is not implemented (optional method).
*
* @throws java.lang.UnsupportedOperationException
* in all cases.
*/
public void remove() {
throw new UnsupportedOperationException("remove");
}
}
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