[HADOOP-11092] hadoop shell commands should print usage if not given a class

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0.0-alpha1
• Component/s: scripts
• Assignee: Allen Wittenauer
• Reporter: Bruno Mahé
• Created: 18/Nov/11 19:27
• Updated: 12/May/16 18:22
• Resolved: 23/Sep/14 19:24

Description

[root@bigtop-fedora-15 ~]# hdfs foobar
Exception in thread "main" java.lang.NoClassDefFoundError: foobar
Caused by: java.lang.ClassNotFoundException: foobar
at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
Could not find the main class: foobar. Program will exit.

Instead of loading any class, it would be nice to explain the command is not valid and to call print_usage()

Issue Links

• duplicates: HDFS-2930 bin/hdfs should print a message when an invalid command is specified
• is related to: HADOOP-11010 Post-9902 "Umbrella" JIRA
• relates to: HADOOP-3281 bin/hadoop script should check class name before running java
• relates to: HADOOP-11150 hadoop command should show the reason on failure by invalid COMMAND or CLASSNAME