hadoop 找不到或无法加载主类org.apache.hado

• hadoop version 3.2.1
• 修改 /mapred-site.xml

<property>
<name>mapreduce.admin.user.env</name> 
<value>HADOOP_MAPRED_HOME=${HADOOP_HOME}</value>
</property>
<property>
<name>yarn.app.mapreduce.am.env</name>
<value>HADOOP_MAPRED_HOME=${HADOOP_HOME}</value>
</property>