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/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common
* Development and Distribution License("CDDL") (collectively, the
* "License"). You may not use this file except in compliance with the
* License. You can obtain a copy of the License at
* http://www.netbeans.org/cddl-gplv2.html
* or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
* specific language governing permissions and limitations under the
* License. When distributing the software, include this License Header
* Notice in each file and include the License file at
* nbbuild/licenses/CDDL-GPL-2-CP. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the GPL Version 2 section of the License file that
* accompanied this code. If applicable, add the following below the
* License Header, with the fields enclosed by brackets [] replaced by
* your own identifying information:
* "Portions Copyrighted [year] [name of copyright owner]"
*
* Contributor(s):
*
* The Original Software is NetBeans. The Initial Developer of the Original
* Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
* Microsystems, Inc. All Rights Reserved.
*
* If you wish your version of this file to be governed by only the CDDL
* or only the GPL Version 2, indicate your decision by adding
* "[Contributor] elects to include this software in this distribution
* under the [CDDL or GPL Version 2] license." If you do not indicate a
* single choice of license, a recipient has the option to distribute
* your version of this file under either the CDDL, the GPL Version 2 or
* to extend the choice of license to its licensees as provided above.
* However, if you add GPL Version 2 code and therefore, elected the GPL
* Version 2 license, then the option applies only if the new code is
* made subject to such option by the copyright holder.
*/
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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