forumiteratorproxy.java

来自「Jive 是一个系统工程」· Java 代码 · 共 105 行

/**
 * $RCSfile: ForumIteratorProxy.java,v $
 * $Revision: 1.2 $
 * $Date: 2000/12/21 17:46:53 $
 *
 * Copyright (C) 2000 CoolServlets.com. All rights reserved.
 *
 * ===================================================================
 * The Apache Software License, Version 1.1
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by
 *        CoolServlets.com (http://www.coolservlets.com)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Jive" and "CoolServlets.com" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please
 *    contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Jive",
 *    nor may "Jive" appear in their name, without prior written
 *    permission of CoolServlets.com.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL COOLSERVLETS.COM OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of CoolServlets.com. For more information
 * on CoolServlets.com, please see <http://www.coolservlets.com>.
 */

package com.coolservlets.forum;

import java.util.*;

/**
 * Protection proxy for Forum iterators. This is a special case iterator proxy
 * because users might not have read access to some of the forums that we
 * need to proxy. The expected behavior is that only forums that users <b>do</b>
 * have read access for will be returned. Therefore, we need to read in the
 * results and only return an iterator for forums that the user can read.
 */
class ForumIteratorProxy extends IteratorProxy {

    private ArrayList forums = new ArrayList();

    public ForumIteratorProxy(Iterator iterator, Authorization
        authorization, ForumPermissions permissions)
    {
        //Dummy call to super-class. This specialized iterator proxy doesn't
        //use the superclass like the other iterators do.
        super(iterator, authorization, permissions);

        while (iterator.hasNext()) {
            Forum forum = (Forum)iterator.next();
            ForumPermissions forumPermissions = forum.getPermissions(authorization);
            //Create a new permissions object with the combination of the
            //permissions of this object and tempPermissions.
            ForumPermissions newPermissions =
                new ForumPermissions(permissions, forumPermissions);
            //Check and see if the user has READ permissions. If not, throw an
            //an UnauthorizedException.
            if (newPermissions.get(ForumPermissions.READ) ||
                    newPermissions.get(ForumPermissions.FORUM_ADMIN) ||
                    newPermissions.get(ForumPermissions.SYSTEM_ADMIN))
            {
                ForumProxy proxy = new ForumProxy(forum, authorization, newPermissions);
                forums.add(proxy);
            }
        }

        this.iterator = forums.listIterator();
    }

    public Object next() throws java.util.NoSuchElementException {
        return iterator.next();
    }
}