The installer of the usersync and unixauthservice can be executed when JAVA_HOME environment variable was set empty. The result is that there are many errors when installing UserSync and unixauthservice. We should handle the exception as well as tagsync.

The installer of the usersync and unixauthservice can be executed when JAVA_HOME environment variable was set empty. The result is that there are many errors when installing UserSync and unixauthservice.

The tagsync installer checked JAVA_HOME environment variable. It would print error information and abort if JAVA_HOME environment variable is empty during installing tagsync. We should handle the exception for the installer of the usersync and unixauthservice as well as tagsync.