// $Id: CollectionUtil.java 10734 2006-06-11 15:43:58Z mvw $
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package org.argouml.util;
import java.util.Collection;
import java.util.List;
/**
* Some helper methods for dealing with collections.
*
* @author Bob Tarling
* @stereotype utility
*/
public final class CollectionUtil {
/**
* Can't construct a utility.
*/
private CollectionUtil() {
}
/**
* Return the first item from a collection using the most efficient
* method possible.
*
* @param c The Collection.
* @return the first element of a Collection.
* @throws java.util.NoSuchElementException if the collection is empty.
*/
public static Object getFirstItem(Collection c) {
if (c instanceof List) {
return ((List) c).get(0);
}
return c.iterator().next();
}
/**
* Return the first item from a collection using the most efficient
* method possible. Returns null for an empty collection.
*
* @param c The Collection.
* @return the first element of a Collection.
*/
public static Object getFirstItemOrNull(Collection c) {
if (c.size() == 0) {
return null;
}
return getFirstItem(c);
}
}