resourcebundleenumeration.java

来自「This is a resource based on j2me embedde」· Java 代码 · 共 79 行

/*
 * @(#)ResourceBundleEnumeration.java	1.6 06/10/10
 *
 * Copyright  1990-2008 Sun Microsystems, Inc. All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 only, as published by the Free Software Foundation. 
 * 
 * This program 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. See the GNU
 * General Public License version 2 for more details (a copy is
 * included at /legal/license.txt). 
 * 
 * You should have received a copy of the GNU General Public License
 * version 2 along with this work; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA 
 * 
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
 * Clara, CA 95054 or visit www.sun.com if you need additional
 * information or have any questions. 
 */

package java.util;

/**
 * Implements an Enumeration that combines elements from a Set and
 * an Enumeration. Used by ListResourceBundle and PropertyResourceBundle.
 */
class ResourceBundleEnumeration implements Enumeration {

    Set set;
    Iterator iterator;
    Enumeration enumeration; // may remain null

    /**
     * Constructs a resource bundle enumeration.
     * @param set an set providing some elements of the enumeration
     * @param enumeration an enumeration providing more elements of the enumeration.
     *        enumeration may be null.
     */
    ResourceBundleEnumeration(Set set, Enumeration enumeration) {
        this.set = set;
        this.iterator = set.iterator();
        this.enumeration = enumeration;
    }

    Object next = null;
            
    public boolean hasMoreElements() {
        if (next == null) {
            if (iterator.hasNext()) {
                next = iterator.next();
            } else if (enumeration != null) {
                while (next == null && enumeration.hasMoreElements()) {
                    next = enumeration.nextElement();
                    if (set.contains(next)) {
                        next = null;
                    }
                }
            }
        }
        return next != null;
    }

    public Object nextElement() {
        if (hasMoreElements()) {
            Object result = next;
            next = null;
            return result;
        } else {
            throw new NoSuchElementException();
        }
    }
}