Error: Failed to Load Class main using Spark-submit

Question

我的代码在下面

import org.apache.spark.SparkContext;
import org.apache.spark.SparkConf;
object WordCounter {
   def main(args: Array[String]) {
     val conf = new SparkConf().setAppName("Word Counter").setMaster("local")
     val sc = new SparkContext(conf)
     val textFile = sc.textFile("C:/spark/README.md")
     val tokenizedFileData = textFile.flatMap(line=>line.split(" "))
     val countPrep = tokenizedFileData.map(word=>(word,1))
     val counts = countPrep.reduceByKey((accumValue,newValue)=> accumValue + newValue)
     val sortedCounts = counts.sortBy(kvPair=>kvPair._2,false)
     sortedCounts.saveAsTextFile("C:/Data/WordCountViaApp")
   }
}

有人可以帮忙吗？

C:\Users\workspace\SparkInScala>spark-submit --class "WordCounter" "C:\Users\workspace\SparkInScala\target\scala-2.12\sparkinscala_2.12-0.1 .0-SNAPSHOT.jar” 错误：无法加载 class WordCounter。

Answer 1

在 build.sbt 文件中使用适当的版本进行更改后，这工作正常。我不再看到错误加载失败 class.

Answer 2

我以前遇到过同样的问题

我正在使用idea的Maven插件开发SparkProgram.Here是我的pom.xml

<build>
    <plugins>
        <plugin>
            <groupId>net.alchim31.maven</groupId>
            <artifactId>scala-maven-plugin</artifactId>
            <version>3.2.2</version>
            <executions>
                <execution>
                    <id>compile-scala</id>
                    <phase>compile</phase>
                    <goals>
                        <goal>add-source</goal>
                        <goal>compile</goal>
                    </goals>
                </execution>
                <execution>
                    <id>test-compile-scala</id>
                    <phase>test-compile</phase>
                    <goals>
                        <goal>add-source</goal>
                        <goal>testCompile</goal>
                    </goals>
                </execution>
            </executions>
            <configuration>
                <scalaVersion>2.12.11</scalaVersion>
            </configuration>
        </plugin>
        <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>
            <artifactId>maven-assembly-plugin</artifactId>
            <configuration>
                <descriptorRefs>
                    <descriptorRef>jar-with-dependencies</descriptorRef>
                </descriptorRefs>
                <archive>
                    <manifest>
                        <mainClass>testConf</mainClass>
                    </manifest>
                </archive>
            </configuration>
            <executions>
                <execution>
                    <id>make-assembly</id>
                    <phase>package</phase>
                    <goals>
                        <goal>assembly</goal>
                    </goals>
                </execution>
            </executions>
        </plugin>

        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>exec-maven-plugin</artifactId>
            <version>1.6.0</version>
            <executions>
                <execution>
                    <goals>
                        <goal>exec</goal>
                    </goals>
                </execution>
            </executions>
            <configuration>
                <executable>java</executable>
                <includeProjectDependencies>true</includeProjectDependencies>
                <includePluginDependencies>false</includePluginDependencies>
                <classpathScope>compile</classpathScope>
                <mainClass>testConf</mainClass>
            </configuration>
        </plugin>
    </plugins>

</build>

您可以尝试将 mainClass 标签“testConf”替换为您的 class 名称和 scala 版本等

Answer 3

如果你想使用SBT那么你必须指定哪个main方法开始执行。

Main-Class: com.WordCounter.main

当你运行 sbt package.

时，上面的内容告诉 SBT 在你的 JAR 中的 META-INF/MANIFEST.MF 文件中添加该行。

当运行使用 SBT 申请时，

sbt "run-main com.WordCounter.main"

此外，正如 Wu 所指出的，Maven 也可以完成这项工作。

Error: Failed to Load Class main using Spark-submit

Error: Failed to Load Class main using Spark-submit

scala

word-count

sbt

apache-spark

spark-submit