akka入門-簡單示例
阿新 • • 發佈:2018-12-25
以下程式演示了akka的一個簡單的示例。建立Actor去處理一條命令,通過訊息傳遞的方式進行互動。
1.建立事件Event
2.建立命令物件
其中主要的方法是重寫onReceive方法,用於處理接收到的訊息。
4.測試類
需要區分的兩個概念是:
actorRef.tell:非同步傳送一個訊息並立即返回;
actorRef.ask:非同步傳送一條訊息並返回一個 Future代表一個可能的迴應;
所以總是使用tell更偏向效能,除非必須才用ask
執行結果:
我使用的akka版本和相關jar包參見pom檔案:
<project xmlns= "http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation= "http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion >4.0.0 </modelVersion> <groupId >com.focusedu.akka </groupId> <artifactId >akka-first</ artifactId> <version >0.0.1-SNAPSHOT </version> <packaging >jar </packaging> <name >akka-first</ name> <url >http://maven.apache.org </url> <properties > <project.build.sourceEncoding> UTF-8</ project.build.sourceEncoding> </properties > <dependencies > <dependency > <groupId >junit</groupId> <artifactId >junit</artifactId> <version >3.8.1 </version> <scope >test </scope> </dependency > <dependency > <groupId> com.typesafe.akka</groupId > <artifactId> akka-actor_2.10 </artifactId> <version> 2.3.10</ version> </dependency > <dependency > <groupId> log4j</ groupId> <artifactId> log4j</ artifactId> <version> 1.2.17</ version> </dependency > <dependency > <groupId> com.google.guava</groupId > <artifactId> guava</artifactId > <version> 18.0</ version> </dependency > <dependency > <groupId> ch.qos.logback</groupId > <artifactId> logback-classic </artifactId> <version> 1.1.1</ version> </dependency > <dependency > <groupId> com.typesafe.akka</groupId > <artifactId> akka-persistence-experimental_2.10 </artifactId> <version> 2.3.10</ version> </dependency > </dependencies > </project>
1.建立事件Event
import java.io.Serializable; public class Event implements Serializable { private String data; private String uuid; public Event(String data) { super(); this. data = data; } public Event(String data, String uuid) { this. data = data; this. uuid = uuid; } public String getData() { return data; } public String getUuid() { return uuid; } @Override public String toString() { return "Event{" + "data='" + data + '\'' + ", uuid='" + uuid + '\'' + '}' ; } }
2.建立命令物件
其中主要的方法是重寫onReceive方法,用於處理接收到的訊息。
3.建立Actor物件import java.io.Serializable; public class Command implements Serializable { private static final long serialVersionUID = 1L; private final String data ; public Command(String data) { this.data = data ; } public String getData() { return this .data ; } @Override public String toString() { return "Command{" + "data='" + data + '\'' + '}'; } }
import java.util.UUID;
import com.center.akka.simple.command.Command;
import com.center.akka.simple.event.Event;
import akka.actor.UntypedActor;
import akka.event.Logging;
import akka.event.LoggingAdapter;
public class SimpleActor extends UntypedActor {
LoggingAdapter log = Logging.getLogger(getContext().system(), this);
public SimpleActor() {
log.info( "SimpleActor constructor");
}
@Override
public void onReceive(Object msg) throws Exception {
log.info( "Received Command: " + msg );
if (msg instanceof Command) {
final String data = ((Command) msg).getData();
final Event event = new Event(data, UUID.randomUUID().toString());
// emmit an event somewhere...
} else if (msg .equals("echo" )) {
log.info( "ECHO!");
}
}
}
4.測試類
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import akka.actor.ActorRef;
import akka.actor.ActorSystem;
import akka.actor.Props;
import com.center.akka.simple.actor.SimpleActor;
import com.center.akka.simple.command.Command;
/**
*
* @author lcq
*
*/
public class System {
public static final Logger log = LoggerFactory.getLogger(System.class);
public static void main(String... args) throws Exception {
final ActorSystem actorSystem = ActorSystem.create("actor-system");
Thread.sleep(5000);
final ActorRef actorRef = actorSystem.actorOf(Props.create(SimpleActor. class), "simple-actor");
actorRef.tell( new Command("CMD 1" ), null);
actorRef.tell( new Command("CMD 2" ), null);
actorRef.tell( new Command("CMD 3" ), null);
actorRef.tell( new Command("CMD 4" ), null);
actorRef.tell( new Command("CMD 5" ), null);
Thread.sleep(5000);
log.debug( "Actor System Shutdown Starting..." );
actorSystem.shutdown();
}
}
需要區分的兩個概念是:
actorRef.tell:非同步傳送一個訊息並立即返回;
actorRef.ask:非同步傳送一條訊息並返回一個 Future代表一個可能的迴應;
所以總是使用tell更偏向效能,除非必須才用ask
執行結果:
[INFO] [05/17/2015 17:46:44.224] [actor-system-akka.actor.default-dispatcher-3] [akka://actor-system/user/simple-actor] SimpleActor constructor
[INFO] [05/17/2015 17:46:44.225] [actor-system-akka.actor.default-dispatcher-3] [akka://actor-system/user/simple-actor] Received Command: Command{data='CMD 1'}
[INFO] [05/17/2015 17:46:44.312] [actor-system-akka.actor.default-dispatcher-3] [akka://actor-system/user/simple-actor] Received Command: Command{data='CMD 2'}
[INFO] [05/17/2015 17:46:44.312] [actor-system-akka.actor.default-dispatcher-3] [akka://actor-system/user/simple-actor] Received Command: Command{data='CMD 3'}
[INFO] [05/17/2015 17:46:44.312] [actor-system-akka.actor.default-dispatcher-3] [akka://actor-system/user/simple-actor] Received Command: Command{data='CMD 4'}
[INFO] [05/17/2015 17:46:44.312] [actor-system-akka.actor.default-dispatcher-3] [akka://actor-system/user/simple-actor] Received Command: Command{data='CMD 5'}
17:46:49.226 [main] DEBUG com.center.akka.simple.app.System - Actor System Shutdown Starting...