Access.java

/*
 * (C) Copyright 2006-2011 Nuxeo SA (http://nuxeo.com/) and others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * Contributors:
 *     Nuxeo - initial API and implementation
 *
 * $Id$
 */

package org.nuxeo.ecm.core.api.security;

import java.io.Serializable;

/**
 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
 */
public final class Access implements Serializable {

    public static final Access GRANT = new Access(1);

    public static final Access DENY = new Access(0);

    public static final Access UNKNOWN = new Access(-1);

    private static final long serialVersionUID = 4797108620404301529L;

    private final int value;

    private Access(int value) {
        this.value = value;
    }

    public int value() {
        return value;
    }

    /**
     * If granted returns true, otherwise returns false.
     *
     * @return true if granted
     */
    public boolean toBoolean() {
        return value > 0;
    }

    @Override
    public String toString() {
        return String.valueOf(value);
    }

    /**
     * Be aware of Java serialization. Avoid initializing another instance than allowed constants.
     *
     * @return GRANT, DENY or UNKNOWN
     */
    private Object readResolve() {
        switch (value) {
        case 1:
            return GRANT;
        case 0:
            return DENY;
        default:
            return UNKNOWN;
        }
    }

}