001/*
002 * (C) Copyright 2006-2011 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Nuxeo - initial API and implementation
018 *
019 * $Id$
020 */
021
022package org.nuxeo.ecm.core.api.security;
023
024import java.io.Serializable;
025
026/**
027 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
028 */
029public final class Access implements Serializable {
030
031    public static final Access GRANT = new Access(1);
032
033    public static final Access DENY = new Access(0);
034
035    public static final Access UNKNOWN = new Access(-1);
036
037    private static final long serialVersionUID = 4797108620404301529L;
038
039    private final int value;
040
041    private Access(int value) {
042        this.value = value;
043    }
044
045    public int value() {
046        return value;
047    }
048
049    /**
050     * If granted returns true, otherwise returns false.
051     *
052     * @return true if granted
053     */
054    public boolean toBoolean() {
055        return value > 0;
056    }
057
058    @Override
059    public String toString() {
060        return String.valueOf(value);
061    }
062
063    /**
064     * Be aware of Java serialization. Avoid initializing another instance than allowed constants.
065     *
066     * @return GRANT, DENY or UNKNOWN
067     */
068    private Object readResolve() {
069        switch (value) {
070        case 1:
071            return GRANT;
072        case 0:
073            return DENY;
074        default:
075            return UNKNOWN;
076        }
077    }
078
079}