one Element Unmodifiable Iterator - Java Collection Framework

Java examples for Collection Framework:Iterator

  1. HOME
  2. Java
  3. Collection Framework
  4. Iterator

Description

one Element Unmodifiable Iterator

Demo Code

/*/*from  w w  w .j  av  a2s. c o  m*/
 * Distributed as part of mchange-commons-java 0.2.9
 *
 * Copyright (C) 2015 Machinery For Change, Inc.
 *
 * Author: Steve Waldman <swaldman@mchange.com>
 *
 * This library is free software; you can redistribute it and/or modify
 * it under the terms of EITHER:
 *
 *     1) The GNU Lesser General Public License (LGPL), version 2.1, as 
 *        published by the Free Software Foundation
 *
 * OR
 *
 *     2) The Eclipse Public License (EPL), version 1.0
 *
 * You may choose which license to accept if you wish to redistribute
 * or modify this work. You may offer derivatives of this work
 * under the license you have chosen, or you may provide the same
 * choice of license which you have been offered here.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * You should have received copies of both LGPL v2.1 and EPL v1.0
 * along with this software; see the files LICENSE-EPL and LICENSE-LGPL.
 * If not, the text of these licenses are currently available at
 *
 * LGPL v2.1: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
 *  EPL v1.0: http://www.eclipse.org/org/documents/epl-v10.php 
 * 
 */
//package com.java2s;
import java.util.*;

public class Main {
    public static Iterator oneElementUnmodifiableIterator(final Object elem) {
        return new Iterator() {
            boolean shot = false;

            public boolean hasNext() {
                return (!shot);
            }

            public Object next() {
                if (shot)
                    throw new NoSuchElementException();
                else {
                    shot = true;
                    return elem;
                }
            }

            public void remove() {
                throw new UnsupportedOperationException(
                        "remove() not supported.");
            }
        };
    }
}

Related Tutorials