forumpermissions.java

来自「Jive是基于JSP/JAVA技术构架的一个大型BBS论坛系统,这是Jive论坛」· Java 代码 · 共 229 行

/**
 * $RCSfile: ForumPermissions.java,v $
 * $Revision: 1.5 $
 * $Date: 2002/04/01 03:54:35 $
 *
 * Copyright (C) 1999-2001 CoolServlets, Inc. All rights reserved.
 *
 * This software is the proprietary information of CoolServlets, Inc.
 * Use is subject to license terms.
 */

package com.jivesoftware.forum;

import com.jivesoftware.util.*;

/**
 * Defines a set of permissions for objects in the forum system that
 * users can be granted. Forum permissions are used by the protection
 * proxy objects defined for each major component of the system.
 */
public class ForumPermissions implements Cacheable {

    /**
     * Permission to read object.
     */
    public static final int READ_FORUM = 0;

    /**
     * Permission to administer the entire sytem.
     */
    public static final int SYSTEM_ADMIN = 1;

    /**
     * Permission to administer a particular forum.
     */
    public static final int FORUM_ADMIN = 2;

    /**
     * Permission to administer a particular user.
     */
    public static final int USER_ADMIN = 3;

    /**
     * Permission to administer a particular group.
     */
    public static final int GROUP_ADMIN = 4;

    /**
     * Permission to moderate threads.
     */
    public static final int MODERATE_THREADS = 5;

    /**
     * Permission to create a new thread.
     */
    public static final int CREATE_THREAD = 6;

    /**
     * Permission to create a new message.
     */
    public static final int CREATE_MESSAGE = 7;

    /**
     * Permission to moderate messages.
     */
    public static final int MODERATE_MESSAGES = 8;

    /**
     * Permission to create attachments.
     */
    public static final int CREATE_ATTACHMENT = 9;

    /**
     * Permission to administer a forum.
     */
    public static final int CATEGORY_ADMIN = 10;

    /**
     * Permission to see a category. In general, this permission shouldn't
     * be used by end-users since it will be automatically toggled for a
     * category if READ_FORUM permissions are enabled on any forum below
     * the category.
     */
    public static final int SHOW_CATEGORY = 11;

    public static final int PERMISSION_COUNT = 12;

    /**
     * Holds the actual permission values.
     */
    //private boolean [] values = new boolean[PERMISSION_COUNT];

    private int value;

    private static final ForumPermissions NO_PERMS =
        new ForumPermissions(false, false, false, false, false, false, false,
                false, false, false, false, false);
    private static final ForumPermissions FULL_PERMS =
        new ForumPermissions(true, true, true, true, true, true, true, true,
                true, true, true, true);
    private static final ForumPermissions READ_ONLY =
        new ForumPermissions(true, false, false, false, false, false, false,
                false, false, false, false, false);

    /**
     * Factory method to create full permissions.
     */
    public static ForumPermissions full() {
        return FULL_PERMS;
    }

    /**
     * Factory method to create an object with no permissions.
     */
    public static ForumPermissions none() {
        return NO_PERMS;
    }

    /**
     * Factory method to create an object with read-only permissions.
     */
    public static ForumPermissions readOnly() {
        return READ_ONLY;
    }

    /**
     * Create a new permissions object with the specified permissions.
     */
    public ForumPermissions(boolean readForum, boolean systemAdmin,
            boolean forumAdmin, boolean userAdmin, boolean groupAdmin,
            boolean moderateThreads, boolean createThread, boolean createMessage,
            boolean moderateMessages, boolean createAttachment,
            boolean categoryAdmin, boolean showCategory)
    {
        value = setBit(value, READ_FORUM, readForum);
        value = setBit(value, SYSTEM_ADMIN, systemAdmin);
        value = setBit(value, FORUM_ADMIN, forumAdmin);
        value = setBit(value, USER_ADMIN, userAdmin);
        value = setBit(value, GROUP_ADMIN, groupAdmin);
        value = setBit(value, MODERATE_THREADS, moderateThreads);
        value = setBit(value, CREATE_THREAD, createThread);
        value = setBit(value, CREATE_MESSAGE, createMessage);
        value = setBit(value, MODERATE_MESSAGES, moderateMessages);
        value = setBit(value, CREATE_ATTACHMENT, createAttachment);
        value = setBit(value, CATEGORY_ADMIN, categoryAdmin);
        value = setBit(value, SHOW_CATEGORY, showCategory);
    }

    /**
     * Returns a bitmask for the selected permissionType and value.
     *
     * @param permissionType the type of permisssion to get the bitmask for.
     * @param value true or false.
     * @return the bitmask associated with the params.
     */
    public static final int setBit(int permissions, int permissionType, boolean value) {
        int mask = 0x1;
        mask = mask << permissionType;
        if (!value) {
            mask = ~mask;
        }
        if (value) {
            return permissions | mask;
        }
        else {
            return permissions & mask;
        }
    }

    /**
     * Creates a new ForumPermission object by combining two permissions
     * objects. The higher permission of each permission type will be used.
     */
    public ForumPermissions(ForumPermissions perm1, ForumPermissions perm2) {
        value = perm1.value | perm2.value;
    }

    /**
     * Creates a new ForumPermissions object using an int. Each bit in the
     * number represents the value for a permission type. Use the getBitMask
     * method in order to easily extract permission data. For example, given
     * a permission int value, you can see if FORUM_ADMIN permissions are
     * enabled with:
     *
     * <ul><tt>1 == (permissions & getBitMask(FORUM_ADMIN, true)</tt></ul>
     *
     * @param permissions a permissions int.
     */
    public ForumPermissions(int permissions) {
        this.value = permissions;
    }

    public String toString() {
        StringBuffer buf = new StringBuffer();
        int copy = value;
        buf.append(String.valueOf(1 == (copy & 0x1)));
        for (int i=1; i<PERMISSION_COUNT; i++) {
            copy = copy >> 1;
            buf.append(",");
            buf.append(String.valueOf(1 == (copy & 0x1)));
        }
        return buf.toString();
    }

    public int toInt() {
        return value;
    }

    /**
     * Returns true if the permission of a particular type is allowed.
     */
    public boolean get(int type) {
        if (type < 0 || type >= PERMISSION_COUNT) {
            return false;
        }
        return 1 == (0x1 & (value >> type));
    }

    //FROM THE CACHEABLE INTERFACE//

    public int getCachedSize() {
        // Approximate the size of the object in bytes by calculating the size
        // of each field.
        int size = 0;
        size += CacheSizes.sizeOfObject();                 // overhead of object
        size += CacheSizes.sizeOfInt();
        return size;
    }
}