Treat an Enumeration as an Iterable
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import java.util.Enumeration;
import java.util.Iterator;
/**
* @since 4.37
* @author Jaroslav Tulach
*/
public class Utils {
/**
* Treat an {@link Enumeration} as an {@link Iterable} so it can be used in an enhanced for-loop.
* Bear in mind that the enumeration is "consumed" by the loop and so should be used only once.
* Generally it is best to put the code which obtains the enumeration inside the loop header.
* <div class="nonnormative">
* <p>Example of correct usage:</p>
* <pre>
* ClassLoader loader = ...;
* String name = ...;
* for (URL resource : NbCollections.iterable(loader.{@link ClassLoader#getResources getResources}(name))) {
* // ...
* }
* </pre>
* </div>
* @param enumeration an enumeration
* @return an iterable wrapper which will traverse the enumeration once
* ({@link Iterator#remove} is not supported)
* @throws NullPointerException if the enumeration is null
* @see <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6349852">Java bug #6349852</a>
* @since org.openide.util 7.5
*/
public static <E> Iterable<E> iterable(final Enumeration<E> enumeration) {
if (enumeration == null) {
throw new NullPointerException();
}
return new Iterable<E>() {
public Iterator<E> iterator() {
return new Iterator<E>() {
public boolean hasNext() {
return enumeration.hasMoreElements();
}
public E next() {
return enumeration.nextElement();
}
public void remove() {
throw new UnsupportedOperationException();
}
};
}
};
}
}
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