我有以下pom.xml。
pom.xml文件

<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>com.datasys.prasanna</groupId>
  <artifactId>hadoop-wordcount</artifactId>
  <version>1.0.0</version>
  <packaging>jar</packaging>
  <name>hadoop-wordcount</name>
  <url>http://maven.apache.org</url>
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>
  <dependencies>
      <dependency>
          <groupId>org.apache.hadoop</groupId>
          <artifactId>hadoop-core</artifactId>
          <version>1.2.1</version>
      </dependency>
  </dependencies>
</project>

当我创建一个类似jar的mvn包时，我得到一个名为 hadoop-wordcount-1.0.0.jar 但是当我尝试像hadoopjar那样运行jar时，hadoop-wordcount-1.0.0.jar wordcount/input/out1
上面写着 Exception in thread "main" java.lang.ClassNotFoundException: WordCount wordcount是一个java文件，它有我的main方法。我在pom.xml中遗漏了什么吗？