Demo-WordCoundOnHadoop:]$ cat input.txt Hello world hello hello Demo-WordCountOnHadoop:]$ docker exec -it hadoop-namenode bash (docker) [root@hadoop-namenode /]# hadoop fs -ls /user/root/ (docker) [root@hadoop-namenode /]# hadoop fs -copyFromLocal input.txt /user/root/input (docker) [root@hadoop-namenode /]# hadoop jar WordCountUsingHadoop-1.0.jar /user/root/input output (docker) [root@hadoop-namenode /]# hadoop fs -ls /user/root/ Found 2 items -rw-r--r-- 2 root supergroup 24 2021-05-24 05:53 /user/root/input drwxr-xr-x - root supergroup 0 2021-05-24 05:57 /user/root/output (docker) [root@hadoop-namenode /]# hadoop fs -ls /user/root/output Found 2 items -rw-r--r-- 2 root supergroup 0 2021-05-24 05:57 /user/root/output/_SUCCESS -rw-r--r-- 2 root supergroup 24 2021-05-24 05:57 /user/root/output/part-r-00000 (docker) [root@hadoop-namenode /]# hadoop fs -cat /user/root/output/part-r-00000 Hello	1 hello	2 world	1