iteratoradapter.java.svn-base

MVC开源框架

/*
 * $Id$
 *
 * 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.
 */
package org.apache.struts.util;

import java.util.Enumeration;
import java.util.Iterator;
import java.util.NoSuchElementException;

/**
 * Utility method for converting Enumeration to an Iterator class.  If you
 * attempt to remove() an Object from the iterator, it will throw an
 * UnsupportedOperationException. Added for use by TagLib so Enumeration can
 * be supported
 *
 * @version $Rev$ $Date: 2005-05-07 12:11:38 -0400 (Sat, 07 May 2005)
 *          $
 */
public class IteratorAdapter implements Iterator {
    private Enumeration e;

    public IteratorAdapter(Enumeration e) {
        this.e = e;
    }

    public boolean hasNext() {
        return e.hasMoreElements();
    }

    public Object next() {
        if (!e.hasMoreElements()) {
            throw new NoSuchElementException(
                "IteratorAdaptor.next() has no more elements");
        }

        return e.nextElement();
    }

    public void remove() {
        throw new UnsupportedOperationException(
            "Method IteratorAdaptor.remove() not implemented");
    }
}