akka学习教程(八) Actor中的Future-询问模式

落日映苍穹つ 2022-07-11 04:18 173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]

和java线程中的future挺像的，可以将一个actor的返回结果重定向到另一个actor中进行处理，主actor或者进程无需等待actor的返回结果。

package akka.future;
    
    import akka.actor.ActorRef;
    import akka.actor.ActorSystem;
    import akka.actor.PoisonPill;
    import akka.actor.Props;
    import akka.pattern.Patterns;
    import com.typesafe.config.ConfigFactory;
    import scala.concurrent.Await;
    import scala.concurrent.Future;
    import scala.concurrent.duration.Duration;
    
    import java.util.concurrent.TimeUnit;
    
    /** * Created by liubenlong on 2017/1/16. */
    public class AskMain { 
    
        public static void main(String[] args) throws Exception {
            ActorSystem system = ActorSystem.create("strategy", ConfigFactory.load("akka.config"));
            ActorRef printActor = system.actorOf(Props.create(PrintActor.class), "PrintActor");
            ActorRef workerActor = system.actorOf(Props.create(WorkerActor.class), "WorkerActor");
    
            //等等future返回
            Future<Object> future = Patterns.ask(workerActor, 5, 1000);
            int result = (int) Await.result(future, Duration.create(3, TimeUnit.SECONDS));
            System.out.println("result:" + result);
    
            //不等待返回值，直接重定向到其他actor，有返回值来的时候将会重定向到printActor
            Future<Object> future1 = Patterns.ask(workerActor, 8, 1000);
            Patterns.pipe(future1, system.dispatcher()).to(printActor);
    
    
            workerActor.tell(PoisonPill.getInstance(), ActorRef.noSender());
        }
    }

package akka.future;
    
    import akka.actor.UntypedActor;
    import akka.event.Logging;
    import akka.event.LoggingAdapter;
    
    /** * Created by liubenlong on 2017/1/12. */
    public class PrintActor extends UntypedActor { 
    
        private final LoggingAdapter log = Logging.getLogger(getContext().system(), this);
    
        @Override
        public void onReceive(Object o) throws Throwable {
            log.info("akka.future.PrintActor.onReceive:" + o);
            if (o instanceof Integer) {
                log.info("print:" + o);
            } else {
                unhandled(o);
            }
        }
    
    }

package akka.future;
    
    import akka.actor.*;
    import akka.event.Logging;
    import akka.event.LoggingAdapter;
    
    /** * Created by liubenlong on 2017/1/12. */
    public class WorkerActor extends UntypedActor { 
    
        private final LoggingAdapter log = Logging.getLogger(getContext().system(), this);
    
        @Override
        public void onReceive(Object o) throws Throwable {
            log.info("akka.future.WorkerActor.onReceive:" + o);
    
            if (o instanceof Integer) {
                Thread.sleep(1000);
                int i = Integer.parseInt(o.toString());
                getSender().tell(i*i, getSelf());
            } else {
                unhandled(o);
            }
        }
    
    }

输出结果：

[INFO] [01/16/2017 16:22:32.983] [strategy-akka.actor.default-dispatcher-5] [akka://strategy/user/WorkerActor] akka.future.WorkerActor.onReceive:5
    result:25
    [INFO] [01/16/2017 16:22:33.984] [strategy-akka.actor.default-dispatcher-5] [akka://strategy/user/WorkerActor] akka.future.WorkerActor.onReceive:8
    [INFO] [01/16/2017 16:22:34.997] [strategy-akka.actor.default-dispatcher-6] [akka://strategy/user/PrintActor] akka.future.PrintActor.onReceive:64
    [INFO] [01/16/2017 16:22:34.997] [strategy-akka.actor.default-dispatcher-6] [akka://strategy/user/PrintActor] print:64

> 其实这里和之前的文章中那样，在workerActor执行完毕以后，向printActor发消息不也行吗？

# 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/