akka学习教程(七) 内置状态转换Procedure

╰半夏微凉° 2022-07-11 04:17 138阅读 0赞

# akka系列文章目录 #

*  [akka学习教程(十四) akka分布式实战][akka_ akka]
 *  [akka学习教程(十三) akka分布式][akka_ akka 1]
 *  [akka学习教程(十二) Spring与Akka的集成][akka_ Spring_Akka]
 *  [akka学习教程(十一) akka持久化][akka_ akka 2]
 *  [akka学习教程(十) agent][akka_ agent]
 *  [akka学习教程(九) STM软件事务内存][akka_ STM]
 *  [akka学习教程(八) Actor中的Future-询问模式][akka_ Actor_Future-]
 *  [akka学习教程(七) 内置状态转换Procedure][akka_ _Procedure]
 *  [akka学习教程(六) 路由器Router][akka_ _Router]
 *  [akka学习教程(五) inbox消息收件箱][akka_ inbox]
 *  [akka学习教程(四) actor生命周期][akka_ actor]
 *  [akka学习教程(三) 不可变对象][akka_]
 *  [akka学习教程(二)HelloWord][akka_HelloWord]
 *  [akka学习教程(一)简介][akka]

在actor运行过程中，可能会有多种状态，各个状态间可能会存在切换的情况，akka已经帮我们考虑到这种情况情况的处理:`Procedure`.  
下面模拟一个婴儿。婴儿有两种不同的状态，开心和生气，婴儿有个特点就是好玩，永远不会累，所以让其睡觉婴儿就会生气，让他继续玩就会很高兴。  
简单代码如下：

package akka;
    
    import akka.actor.*;
    import akka.event.Logging;
    import akka.event.LoggingAdapter;
    import akka.japi.Procedure;
    import com.typesafe.config.ConfigFactory;
    
    /** * Created by liubenlong on 2017/1/12. */
    public class ProcedureTest extends UntypedActor { 
    
        private final LoggingAdapter log = Logging.getLogger(getContext().system(), this);
    
        Procedure<Object> happy = new Procedure<Object>() {
            @Override
            public void apply(Object o) throws Exception {
                log.info("i am happy! " + o);
                if (o == Msg.PLAY) {
                    getSender().tell("i am alrady happy!!", getSelf());
                    log.info("i am alrady happy!!");
                } else if (o == Msg.SLEEP) {
                    log.info("i do not like sleep!");
                    getContext().become(angray);
                } else {
                    unhandled(o);
                }
            }
        };
    
        Procedure<Object> angray = new Procedure<Object>() {
            @Override
            public void apply(Object o) throws Exception {
                log.info("i am angray! "+o);
                if(o ==Msg.SLEEP){
                    getSender().tell("i am alrady angray!!", getSelf());
                    log.info("i am alrady angray!!");
                } else if(o ==Msg.PLAY) {
                    log.info("i like play.");
                    getContext().become(happy);
                } else {
                    unhandled(o);
                }
            }
        };
    
    
        @Override
        public void onReceive(Object o) throws Throwable {
            log.info("onReceive msg: " + o);
            if(o == Msg.SLEEP){
                getContext().become(angray);
            }else if(o == Msg.PLAY){
                getContext().become(happy);
            }else {
                unhandled(o);
            }
    
        }
    
    
    
        public static void main(String[] args) throws InterruptedException {
            ActorSystem system = ActorSystem.create("strategy", ConfigFactory.load("akka.config"));
            ActorRef procedureTest = system.actorOf(Props.create(ProcedureTest.class), "ProcedureTest");
    
            procedureTest.tell(Msg.PLAY, ActorRef.noSender());
            procedureTest.tell(Msg.SLEEP, ActorRef.noSender());
            procedureTest.tell(Msg.PLAY, ActorRef.noSender());
            procedureTest.tell(Msg.PLAY, ActorRef.noSender());
    
            procedureTest.tell(PoisonPill.getInstance(), ActorRef.noSender());
        }
    }

输出结果：

[INFO] [01/16/2017 15:50:53.967] [strategy-akka.actor.default-dispatcher-2] [akka://strategy/user/ProcedureTest] onReceive msg: PLAY
    [INFO] [01/16/2017 15:50:54.000] [strategy-akka.actor.default-dispatcher-2] [akka://strategy/user/ProcedureTest] i am happy! SLEEP
    [INFO] [01/16/2017 15:50:54.000] [strategy-akka.actor.default-dispatcher-2] [akka://strategy/user/ProcedureTest] i do not like sleep!
    [INFO] [01/16/2017 15:50:54.000] [strategy-akka.actor.default-dispatcher-2] [akka://strategy/user/ProcedureTest] i am angray! PLAY
    [INFO] [01/16/2017 15:50:54.000] [strategy-akka.actor.default-dispatcher-2] [akka://strategy/user/ProcedureTest] i like play.
    [INFO] [01/16/2017 15:50:54.000] [strategy-akka.actor.default-dispatcher-2] [akka://strategy/user/ProcedureTest] i am happy! PLAY
    [INFO] [01/16/2017 15:50:54.004] [strategy-akka.actor.default-dispatcher-2] [akka://strategy/user/ProcedureTest] i am alrady happy!!

注意：

*  `akka.ProcedureTest#onReceive`这个方法只被调用一次，只有的切换均在`procedure`中处理，所以在实际开发过程中要注意状态切换的准确性。

# 参考资料 #

*  书籍《java高并发程序设计》
 *  [AKKA官方文档][AKKA]

[akka_ akka]: http://blog.csdn.net/liubenlong007/article/details/54603296
[akka_ akka 1]: http://blog.csdn.net/liubenlong007/article/details/54601998
[akka_ Spring_Akka]: http://blog.csdn.net/liubenlong007/article/details/54601448
[akka_ akka 2]: http://blog.csdn.net/liubenlong007/article/details/54584303
[akka_ agent]: http://blog.csdn.net/liubenlong007/article/details/54576611
[akka_ STM]: http://blog.csdn.net/liubenlong007/article/details/54576412
[akka_ Actor_Future-]: http://blog.csdn.net/liubenlong007/article/details/54575312
[akka_ _Procedure]: http://blog.csdn.net/liubenlong007/article/details/54574878
[akka_ _Router]: http://blog.csdn.net/liubenlong007/article/details/54574064
[akka_ inbox]: http://blog.csdn.net/liubenlong007/article/details/54377820
[akka_ actor]: http://blog.csdn.net/liubenlong007/article/details/54093889
[akka_]: http://blog.csdn.net/liubenlong007/article/details/54093794
[akka_HelloWord]: http://blog.csdn.net/liubenlong007/article/details/53782971
[akka]: http://blog.csdn.net/liubenlong007/article/details/53782966
[AKKA]: http://akka.io/docs/