不能解析符號ValueState

Question

我試圖使用弗林克-流狀態的後端，這個指南：https://ci.apache.org/projects/flink/flink-docs-master/apis/streaming/state.html，但我得到的錯誤：無法解析符號「ValueState」。

看了一下之後，我意識到ValueState不在我的依賴關係中。相反，只有運營商位於org.apache.flink.api.common.state（flink-core）中。

不過，如果我看在Github上，我看到ValueState在該包：https://github.com/apache/flink/tree/master/flink-core/src/main/java/org/apache/flink/api/common/state

我猜我要麼沒有弗林克的正確版本使用StateBackend引導顯示的方式，或者也許我有正確的版本，但ValueState已被移至另一個Maven依賴項。

下面是我的pom.xml：

<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>test</groupId> 
<artifactId>flink-streaming</artifactId> 
<version>1.0-SNAPSHOT</version> 
<packaging>jar</packaging> 

<name>flink-streaming</name> 
<url>http://maven.apache.org</url> 

<properties> 
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> 
    <!--<flink.version>0.10.2</flink.version>--> 
    <flink.version>0.10.2</flink.version> 
    <scala.version>2.11.8</scala.version> 
    <scala.dependency.version>2.11</scala.dependency.version> 
</properties> 


<dependencies> 
    <dependency> 
     <groupId>org.scala-lang</groupId> 
     <artifactId>scala-library</artifactId> 
     <version>${scala.version}</version> 
    </dependency> 
    <dependency> 
     <groupId>org.apache.flink</groupId> 
     <artifactId>flink-scala_${scala.dependency.version}</artifactId> 
     <version>${flink.version}</version> 
    </dependency> 
    <dependency> 
     <groupId>org.apache.flink</groupId> 
     <artifactId>flink-clients_${scala.dependency.version}</artifactId> 
     <version>${flink.version}</version> 
    </dependency> 
    <dependency> 
     <groupId>org.apache.flink</groupId> 
     <artifactId>flink-streaming-scala_${scala.dependency.version}</artifactId> 
     <version>${flink.version}</version> 
    </dependency> 
</dependencies> 

<build> 
    <plugins> 
     <plugin> 
      <artifactId>maven-compiler-plugin</artifactId> 
      <version>2.3.2</version> 
      <configuration> 
       <source>1.7</source> 
       <target>1.7</target> 
      </configuration> 
     </plugin> 

     <plugin> 
      <groupId>org.scala-tools</groupId> 
      <artifactId>maven-scala-plugin</artifactId> 
      <executions> 
       <execution> 
        <goals> 
         <goal>compile</goal> 
         <goal>testCompile</goal> 
        </goals> 
       </execution> 
      </executions> 
      <configuration> 
       <jvmArgs> 
        <jvmArg>-Xms64m</jvmArg> 
        <jvmArg>-Xmx1024m</jvmArg> 
       </jvmArgs> 
      </configuration> 
     </plugin> 

    </plugins> 
</build> 

這裏是我的代碼：

import org.apache.flink.api.common.functions.RichFlatMapFunction; 
import org.apache.flink.api.java.tuple.Tuple2; 
import org.apache.flink.util.Collector; 


public class CountWindowAverage extends RichFlatMapFunction<Tuple2<Long,Long>, Tuple2<Long,Long>> { 
    private transient ValueState<Tuple2<Long,Long>> sum; 

    @Override 
    public void flatMap(Tuple2<Long,Long> input, Collector<Tuple2<Long,Long>> out) throws Exception { 

    } 
} 

非常感謝提前對你的幫助！

Laurent。

Answer 1

你是對的Flink版本0.10.x還沒有ValueState。如果您至少切換到版本1.0.0，您應該沒問題。