Question

我刚刚开始学习AKKA，并从学习AKKA这本书中编写了一个示例程序，但该程序没有运行，也没有为进一步调试提供任何有用的信息。我正在粘贴下面的代码文件，请查看并提供

SetRequest.java

package com.akkademy.messages;

public class SetRequest {
    private  String key;
    private  String value;

    public  SetRequest(String key, String value) {
        this.key = key;
        this.value = value;
    }

    public String getKey() {
        return key;
    }

    public String getValue() {
        return value;
    }
}

AkkademyDB.java

package com.akkademy;

import akka.actor.AbstractActor;
import akka.event.Logging;
import akka.event.LoggingAdapter;
import akka.japi.pf.ReceiveBuilder;
import com.akkademy.messages.SetRequest;

import java.util.HashMap;
import java.util.Map;

public class AkkademyDB extends AbstractActor{

    protected final LoggingAdapter log  = Logging.getLogger(context().system(),this);
    protected final Map<String,Object> map = new HashMap<>();

    private AkkademyDB(){
        receive(ReceiveBuilder.match(SetRequest.class,message->{
            log.info("Received set request-key:{} value: {}",message.getKey(),message.getValue());
        }).matchAny(o->log.info("received unknown message {}",o)).build()
        );
    }


}

AkkademyDBTest.java

package com.akkademy;

import akka.actor.ActorSystem;
import akka.actor.Props;
import akka.testkit.TestActorRef;
import com.akkademy.messages.SetRequest;
import akka.actor.ActorRef;
import org.junit.Test;

import static junit.framework.Assert.assertEquals;


public class AkkademyDBTest {

    ActorSystem system =  ActorSystem.create();

    @Test
    public void itShouldPlaceKeyValueFromSetMessageIntoMap() {
        TestActorRef<AkkademyDB> actorRef = TestActorRef.create(system, Props.create(AkkademyDB.class));
        actorRef.tell(new SetRequest("key","value"),ActorRef.noSender());
        AkkademyDB akkademyDB = actorRef.underlyingActor();
        assertEquals(akkademyDB.map.get("key"),"value");


    }
}

build.sbt

name := """akkademy-db"""

version := "1.0"

scalaVersion := "2.11.1"

libraryDependencies ++= Seq(
  "com.typesafe.akka" % "akka-actor_2.11" % "2.3.6",
  "com.typesafe.akka" % "akka-testkit_2.11" % "2.5.6" % "test",
  "junit" % "junit" % "4.12" % "test",
  "com.novocode" % "junit-interface" % "0.10" % "test")

运行测试文件时收到错误消息

/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/bin/java -ea -Didea.test.cyclic.buffer.size=1048576 -Dfile.encoding=UTF-8 -classpath "/Applications/IntelliJ IDEA.app/Contents/lib/idea_rt.jar:/Applications/IntelliJ IDEA.app/Contents/plugins/junit/lib/junit-rt.jar:/Applications/IntelliJ IDEA.app/Contents/plugins/junit/lib/junit5-rt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/charsets.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/deploy.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/ext/cldrdata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/ext/dnsns.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/ext/jaccess.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/ext/jfxrt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/ext/localedata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/ext/nashorn.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/ext/sunec.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/ext/sunjce_provider.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/ext/sunpkcs11.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/ext/zipfs.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/javaws.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/jce.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/jfr.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/jfxswt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/jsse.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/management-agent.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/plugin.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/resources.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/jre/lib/rt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/lib/ant-javafx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/lib/dt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/lib/javafx-mx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/lib/jconsole.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/lib/packager.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/lib/sa-jdi.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home/lib/tools.jar:/Users/madhurjain/akkademy-db/target/scala-2.11/test-classes:/Users/madhurjain/akkademy-db/target/scala-2.11/classes:/Users/madhurjain/.ivy2/cache/org.scala-lang/scala-library/jars/scala-library-2.11.2.jar:/Users/madhurjain/.ivy2/cache/com.typesafe.akka/akka-actor_2.11/jars/akka-actor_2.11-2.3.6.jar:/Users/madhurjain/.ivy2/cache/com.typesafe/config/bundles/config-1.2.1.jar:/Users/madhurjain/.ivy2/cache/org.scala-tools.testing/test-interface/jars/test-interface-0.5.jar:/Users/madhurjain/.ivy2/cache/junit/junit-dep/jars/junit-dep-4.10.jar:/Users/madhurjain/.ivy2/cache/com.novocode/junit-interface/jars/junit-interface-0.10.jar:/Users/madhurjain/.ivy2/cache/com.typesafe/config/bundles/config-1.3.1.jar:/Users/madhurjain/.ivy2/cache/com.typesafe.akka/akka-actor_2.11/jars/akka-actor_2.11-2.5.6.jar:/Users/madhurjain/.ivy2/cache/com.typesafe.akka/akka-testkit_2.11/jars/akka-testkit_2.11-2.5.6.jar:/Users/madhurjain/.ivy2/cache/org.scala-lang/scala-library/jars/scala-library-2.11.11.jar:/Users/madhurjain/.ivy2/cache/org.scala-lang.modules/scala-java8-compat_2.11/bundles/scala-java8-compat_2.11-0.7.0.jar:/Users/madhurjain/.ivy2/cache/junit/junit/jars/junit-4.12.jar:/Users/madhurjain/.ivy2/cache/org.hamcrest/hamcrest-core/jars/hamcrest-core-1.3.jar" com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 com.akkademy.AkkademyDBTest
[INFO] [10/25/2017 17:59:59.509] [main] [akka://default/user/$$a] Received set request-key:key value: value

junit.framework.AssertionFailedError: 
Expected :null
Actual   :value
 <Click to see difference>


    at junit.framework.Assert.fail(Assert.java:50)
    at junit.framework.Assert.failNotEquals(Assert.java:287)
    at junit.framework.Assert.assertEquals(Assert.java:67)
    at junit.framework.Assert.assertEquals(Assert.java:74)
    at com.akkademy.AkkademyDBTest.itShouldPlaceKeyValueFromSetMessageIntoMap(AkkademyDBTest.java:22)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:157)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

Answer 1

当AcademyDB actor收到SetRequest消息时，它不会将消息的键和值放在其内部映射中，而只是记录键和值。您的测试失败，因为它检查了actor的键值对的映射并且什么也没找到。

更改您的actor以将SetRequest消息的键值对放在其地图中：

public class AkkademyDB extends AbstractActor {
    protected final LoggingAdapter log = Logging.getLogger(getContext().getSystem(), this);
    protected final Map<String, Object> map = new HashMap<>();

    @Override
    public Receive createReceive() {
        return receiveBuilder()
            .match(SetRequest.class, message -> {
                log.info("Received set request-key:{} value: {}", message.getKey(), message.getValue());
                map.put(message.getKey(), message.getValue()); // <--- put in map
            })
            .matchAny(o -> log.info("received unknown message {}", o))
            .build();
    }
}

此外，调整您的build.sbt以始终使用Akka罐子的2.5.6版本：

name := "akkademy-db"

version := "1.0"

scalaVersion := "2.11.11"

val akkaVersion = "2.5.6"

libraryDependencies ++= Seq(
  "com.typesafe.akka" %% "akka-actor" % akkaVersion,
  "com.typesafe.akka" %% "akka-testkit" % akkaVersion,
  "junit" % "junit" % "4.12" % "test",
  "com.novocode" % "junit-interface" % "0.10" % "test")

Akka基本程序不起作用

1 个答案: