java - Spark2.2.1 不兼容 Jackson 版本 2.8.8

Question

我的配置是:

• Scala 2.11(插件 Scala IDE)
• Eclipse Neon.3 版本 (4.6.3)
• Windows 7 64 位

我想运行这个简单的 scala 代码 (Esempio.scala):

package it.scala

// importo packages di Spark
import org.apache.spark.SparkContext
import org.apache.spark.SparkConf


object Wordcount {
    def main(args: Array[String]) {

        val inputs: Array[String] = new Array[String](2)
        inputs(0) = "C:\\Users\\FobiDell\\Desktop\\input"
        inputs(1) = "C:\\Users\\FobiDell\\Desktop\\output"

        // oggetto SparkConf per settare i parametri sulla propria applicazione 
        // da fornire poi al cluster manager scelto (Yarn, Mesos o Standalone).
        val conf = new SparkConf()
        conf.setAppName("Smartphone Addiction")
        conf.setMaster("local")

        // oggetto SparkContext per connessione al cluster manager scelto
        val sc = new SparkContext(conf)

        //Read file and create RDD
        val rawData = sc.textFile(inputs(0))

        //convert the lines into words using flatMap operation
        val words = rawData.flatMap(line => line.split(" "))

        //count the individual words using map and reduceByKey operation
        val wordCount = words.map(word => (word, 1)).reduceByKey(_ + _)

        //Save the result
        wordCount.saveAsTextFile(inputs(1))

       //stop the spark context
       sc.stop

   }

}

因此，如果我使用 Spark-shell 一切正常，否则，如果我从 Eclipse IDE 选择文件 (Esempio.scala) 并通过 Run->Run as->Scala application 运行它，我将获得此异常:

Exception in thread "main" java.lang.ExceptionInInitializerError
    at org.apache.spark.SparkContext.withScope(SparkContext.scala:701)
    at org.apache.spark.SparkContext.textFile(SparkContext.scala:830)
    at it.scala.Wordcount$.main(Esempio.scala:47)
    at it.scala.Wordcount.main(Esempio.scala)
Caused by: com.fasterxml.jackson.databind.JsonMappingException: Incompatible Jackson version: 2.8.8
    at com.fasterxml.jackson.module.scala.JacksonModule$class.setupModule(JacksonModule.scala:64)
    at com.fasterxml.jackson.module.scala.DefaultScalaModule.setupModule(DefaultScalaModule.scala:19)
    at com.fasterxml.jackson.databind.ObjectMapper.registerModule(ObjectMapper.java:745)
    at org.apache.spark.rdd.RDDOperationScope$.<init>(RDDOperationScope.scala:82)
    at org.apache.spark.rdd.RDDOperationScope$.<clinit>(RDDOperationScope.scala)
    ... 4 more  

我的 pom.xml 文件是:

<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>it.hgfhgf.xhgfghf</groupId>
  <artifactId>progetto</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>progetto</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>

    <!-- Neo4j JDBC DRIVER -->
    <dependency>
      <groupId>org.neo4j</groupId>
      <artifactId>neo4j-jdbc-driver</artifactId>
      <version>3.1.0</version>
    </dependency>

    <!-- Scala -->
    <dependency>
      <groupId>org.scala-lang</groupId>
      <artifactId>scala-library</artifactId>
      <version>2.11.11</version>
    </dependency> 

    <!-- Spark -->
    <dependency>
      <groupId>org.apache.spark</groupId>
      <artifactId>spark-core_2.11</artifactId>
      <version>2.2.1</version>
    </dependency>


  </dependencies>


</project>

我注意到 spark-2.2.1-bin-hadoop2.7/jars 目录中的 .jar 文件是:

• jackson-core-2.6.5.jar
• jackson-databind-2.6.5.jar
• jackson-module-paranamer-2.6.5.jar
• jackson-module-scala_2.11-2.6.5.jar
• jackson-annotations-2.6.5.jar

谁能用简单的语言向我解释这个异常是什么以及如何解决它？

Answer 1

Spark 2.x 包含 jackson 2.6.5 和 neo4j-jdbc-driver 使用 jackson 2.8.8 版本，这里是依赖两个不同版本的 jackson 库之间的冲突。 这就是您收到此 Incompatible Jackson version: 2.8.8 错误的原因。

尝试在 pom.xml 中覆盖这些 [below] 模块的依赖版本，看看是否有效，

1. jackson 核心
2. jackson 数据绑定(bind)
3. jackson-module-scala_2.x

或尝试将以下依赖项添加到您的 pom.xml

        <dependency>
            <groupId>com.fasterxml.jackson.module</groupId>
            <artifactId>jackson-module-scala_2.11</artifactId>
            <version>2.8.8</version>
        </dependency>