java.lang.NoClassDefFoundError：COM /類型安全/配置/配置，同時運行在STS阿卡 - 快速入門的Java

Question

我想在春天工具套件運行http://developer.lightbend.com/guides/akka-quickstart-java/ 提供的項目（日蝕）是

文件如下：

1.AkkaQuickstart.java

import java.io.IOException; 
import akka.actor.ActorRef; 
import akka.actor.ActorSystem; 

public class AkkaQuickstart { 
    public static void main(String[] args) { 
    final ActorSystem system = ActorSystem.create("helloakka"); 
    try { 
     //#create-actors 
     final ActorRef printerActor = 
     system.actorOf(Printer.props(), "printerActor"); 
     final ActorRef howdyGreeter = 
     system.actorOf(Greeter.props("Howdy", printerActor), "howdyGreeter"); 
     final ActorRef helloGreeter = 
     system.actorOf(Greeter.props("Hello", printerActor), "helloGreeter"); 
     final ActorRef goodDayGreeter = 
     system.actorOf(Greeter.props("Good day", printerActor), "goodDayGreeter"); 
     //#create-actors 

     //#main-send-messages 
     howdyGreeter.tell(new WhoToGreet("Akka"), ActorRef.noSender()); 
     howdyGreeter.tell(new Greet(), ActorRef.noSender()); 

     howdyGreeter.tell(new WhoToGreet("Lightbend"), ActorRef.noSender()); 
     howdyGreeter.tell(new Greet(), ActorRef.noSender()); 

     helloGreeter.tell(new WhoToGreet("Java"), ActorRef.noSender()); 
     helloGreeter.tell(new Greet(), ActorRef.noSender()); 

     goodDayGreeter.tell(new WhoToGreet("Play"), ActorRef.noSender()); 
     goodDayGreeter.tell(new Greet(), ActorRef.noSender()); 
     //#main-send-messages 

     System.out.println(">>> Press ENTER to exit <<<"); 
     System.in.read(); 
    } catch (IOException ioe) { 
    } finally { 
     system.terminate(); 
    } 
    } 
} 

2.Greeter.java

import akka.actor.AbstractActor; 
import akka.actor.ActorRef; 
import akka.actor.Props; 

//#greeter-messages 
public class Greeter extends AbstractActor { 
//#greeter-messages 
    static public Props props(String message, ActorRef printerActor) { 
    return Props.create(Greeter.class,() -> new Greeter(message, printerActor)); 
    } 

    //#greeter-messages 
    static public class WhoToGreet { 
    public final String who; 

    public WhoToGreet(String who) { 
     this.who = who; 
    } 
    } 

    static public class Greet { 
    public Greet() { 
    } 
    } 
    //#greeter-messages 

    private final String message; 
    private final ActorRef printerActor; 
    private String greeting = ""; 

    public Greeter(String message, ActorRef printerActor) { 
    this.message = message; 
    this.printerActor = printerActor; 
    } 

    @Override 
    public Receive createReceive() { 
    return receiveBuilder() 
     .match(WhoToGreet.class, wtg -> { 
      this.greeting = message + ", " + wtg.who; 
     }) 
     .match(Greet.class, x -> { 
      //#greeter-send-message 
      printerActor.tell(new Greeting(greeting), getSelf()); 
      //#greeter-send-message 
     }) 
     .build(); 
    } 
//#greeter-messages 
} 
//#greeter-messages 

3.Printer.java

import akka.actor.AbstractActor; 
    import akka.actor.Props; 
    import akka.event.Logging; 
    import akka.event.LoggingAdapter; 

    //#printer-messages 
    public class Printer extends AbstractActor { 
    //#printer-messages 
     static public Props props() { 
     return Props.create(Printer.class,() -> new Printer()); 
     } 

     //#printer-messages 
     static public class Greeting { 
     public final String message; 

     public Greeting(String message) { 
      this.message = message; 
     } 
     } 
     //#printer-messages 

     private LoggingAdapter log = Logging.getLogger(getContext().getSystem(), this); 

     public Printer() { 
     } 

     @Override 
     public Receive createReceive() { 
     return receiveBuilder() 
      .match(Greeting.class, greeting -> { 
       log.info(greeting.message); 
      }) 
      .build(); 
     } 
    //#printer-messages 
    } 
    //#printer-messages 

4.pom.xml

<!-- #build-sample --> 
     <project> 
     <modelVersion>4.0.0</modelVersion> 

     <groupId>hello-akka-java</groupId> 
     <artifactId>app</artifactId> 
     <version>1.0</version> 

     <dependencies> 
      <dependency> 
       <groupId>com.typesafe.akka</groupId> 
       <artifactId>akka-actor_2.12</artifactId> 
       <version>2.5.2</version> 
      </dependency> 
      <dependency> 
       <groupId>com.typesafe.akka</groupId> 
       <artifactId>akka-testkit_2.12</artifactId> 
       <version>2.5.2</version> 
      </dependency> 
      <dependency> 
       <groupId>junit</groupId> 
       <artifactId>junit</artifactId> 
       <version>4.12</version> 
      </dependency> 
     </dependencies> 
     <build> 
      <plugins> 
       <plugin> 
        <groupId>org.apache.maven.plugins</groupId> 
        <artifactId>maven-compiler-plugin</artifactId> 
        <version>3.5.1</version> 
        <configuration> 
         <source>1.8</source> 
         <target>1.8</target> 
        </configuration> 
       </plugin> 
       <plugin> 
        <groupId>org.codehaus.mojo</groupId> 
        <artifactId>exec-maven-plugin</artifactId> 
        <version>1.6.0</version> 
        <configuration> 
         <executable>java</executable> 
         <arguments> 
          <argument>-classpath</argument> 
          <classpath /> 
          <argument>com.lightbend.akka.sample.AkkaQuickstart</argument> 
         </arguments> 
        </configuration> 
       </plugin> 
      </plugins> 
     </build> 
     </project> 

我試圖運行Maven構建：MVN全新安裝： 輸出是：

... 
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ app --- 
[INFO] Surefire report directory: /Users/xxx/Downloads/akka-quickstart-java/target/surefire-reports 

------------------------------------------------------- 
T E S T S 
------------------------------------------------------- 
Running com.lightbend.akka.sample.AkkaQuickstartTest 
Tests run: 2, Failures: 0, Errors: 2, Skipped: 0, Time elapsed: 0.555 sec <<< FAILURE! 
com.lightbend.akka.sample.AkkaQuickstartTest Time elapsed: 0.555 sec <<< ERROR! 
java.lang.BootstrapMethodError: java.lang.NoClassDefFoundError: com/typesafe/config/Config 
    at akka.actor.ActorSystem$.apply(ActorSystem.scala:241) 
    at akka.actor.ActorSystem$.apply(ActorSystem.scala:287) 
    at akka.actor.ActorSystem$.apply(ActorSystem.scala:232) 
    at akka.actor.ActorSystem$.apply(ActorSystem.scala:223) 
    at akka.actor.ActorSystem$.create(ActorSystem.scala:158) 
    at akka.actor.ActorSystem.create(ActorSystem.scala) 
    at com.lightbend.akka.sample.AkkaQuickstartTest.setup(AkkaQuickstartTest.java:20) 
... 

我在這裏錯過了什麼？

Answer 1

你缺少的主要com.typesafe dependency.In你的pom.xml添加

<dependency> 
    <groupId>com.typesafe</groupId> 
    <artifactId>config</artifactId> 
    <version>1.2.1</version> 
</dependency> 

java.lang.NoClassDefFoundError主要是由於缺少依賴/瓶。 希望幫助