我当前的/etc/profile文件配置的环境变量

export JAVA_HOME=/opt/java/jdk1.8.0_131
export SPARK_HOME=/opt/spark-2.4.4-bin-hadoop2.7
export HIVE_HOME=/usr/hdp/current/hive-client
export LIVY_HOME=/opt/livy/livy-0.5.0-incubating-bin
export HBASE_HOME=/opt/hbase-2.2.1
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
export HADOOP_HOME=/opt/hadoop-2.7.7
export HADOOP_COMMON_HOME=$HADOOP_HOME
export HADOOP_MAPRED_HOME=$HADOOP_HOME
export HADOOP_YARN_HOME=$HADOOP_HOME
export HADOOP_CONF_DIR=$HADOOP_HOME/etc/hadoop
export HADOOP_USER_NAME=hdfs
export HADOOP_HDFS_HOME=$HADOOP_HOME
export HADOOP_HDFS_HOME=$HADOOP_HOME
export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin:/usr/local/go/bin
export PATH=$JAVA_HOME/bin:$HADOOP_HOME/bin:$SPARK_HOME/bin:$LIVY_HOME/bin:$PATH

当配置完环境变量于是我准备开始测试一下，于是遇到了如下报错
hadoop fs -ls / 查看hdfs文件

#执行hadoop classpath 命令会显示当前hadoop都引入了那些jar包

解决方法如下
libexec/hadoop-config.sh 这个文件里最后一行

添加CLASSPATH=${CLASSPATH}:'/opt/hadoop-2.7.7/client/*

再次查看hadoop fs -ls /