001 /*
002 * ============================================================================
003 * GNU Lesser General Public License
004 * ============================================================================
005 *
006 * Beanlet - JSE Application Container.
007 * Copyright (C) 2006 Leon van Zantvoort
008 *
009 * This library is free software; you can redistribute it and/or
010 * modify it under the terms of the GNU Lesser General Public
011 * License as published by the Free Software Foundation; either
012 * version 2.1 of the License, or (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful,
015 * but WITHOUT ANY WARRANTY; without even the implied warranty of
016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
017 * Lesser General Public License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
022 *
023 * Leon van Zantvoort
024 * 243 Acalanes Drive #11
025 * Sunnyvale, CA 94086
026 * USA
027 *
028 * zantvoort@users.sourceforge.net
029 * http://beanlet.org
030 */
031 package org.beanlet;
032
033 import java.lang.annotation.ElementType;
034 import java.lang.annotation.Retention;
035 import java.lang.annotation.RetentionPolicy;
036 import java.lang.annotation.Target;
037
038 /**
039 * <p>Stateless beanlets do not share any state between subsequent method
040 * invocations. Stateless beanlet instances are pooled and methods called on
041 * stateless beanlet stubs are delegated to one of the pooled instances.
042 * If multiple invocations are made on the same stub reference, different
043 * beanlet instances can be used to perform the call.<br>
044 * Beanlet instances are added and removed from the pool at the container's
045 * discretion. Requesting a beanlet stub through the APIs, or dependency
046 * injection does not necessarily result in the creation of a new beanlet
047 * instance. In general, the number of pooled beanlet instances depends on the
048 * number of concurrent requests made to these stubs.</br>
049 * Stateless beanlets can be configured to be {@code reentrant} and
050 * {@code singleton}.</p>
051 *
052 * {@beanlet.annotation}
053 *
054 * @see Stateful
055 * @see ScopeAnnotation
056 * @author Leon van Zantvoort
057 */
058 @ScopeAnnotation
059 @Retention(RetentionPolicy.RUNTIME)
060 @Target(ElementType.TYPE)
061 public @interface Stateless {
062
063 /**
064 * Set to {@code true} to declare this beanlet to be a singleton beanlet.
065 * Only one beanlet instance will exist at the same time for singleton
066 * beanlets.
067 */
068 boolean singleton() default false;
069
070 /**
071 * Specifies whether the beanlet instances should be reentrant or not.
072 * Instances of reentrant beanlets can be invoked by multiple threads at
073 * the same time.
074 */
075 boolean reentrant() default false;
076 }