Why I had this failure?!!!
root@ubuntutestdev:/opt# service solr status ● solr.service - LSB: Controls Apache Solr as a Service Loaded: loaded (/etc/init.d/solr) Active: failed (Result: exit-code) since Wed 2029-01-03 08:29:11 EET; 12 years 9 months left Docs: man:systemd-sysv-generator(8) Process: 598 ExecStart=/etc/init.d/solr start (code=exited, status=1/FAILURE) Jan 03 08:29:11 ubuntutestdev solr[598]: Java not found, or an error was enc.... Jan 03 08:29:11 ubuntutestdev solr[598]: A working Java 7 or later is requir...! Jan 03 08:29:11 ubuntutestdev solr[598]: Please install Java or fix JAVA_HOM.... Jan 03 08:29:11 ubuntutestdev solr[598]: Command that we tried: 'java -version' Jan 03 08:29:11 ubuntutestdev solr[598]: Active Path: Jan 03 08:29:11 ubuntutestdev solr[598]: /usr/local/bin:/usr/bin:/bin:/usr/l...s Jan 03 08:29:11 ubuntutestdev systemd[1]: solr.service: Control process exit...1 Jan 03 08:29:11 ubuntutestdev systemd[1]: Failed to start LSB: Controls Apac.... Jan 03 08:29:11 ubuntutestdev systemd[1]: solr.service: Unit entered failed .... Jan 03 08:29:11 ubuntutestdev systemd[1]: solr.service: Failed with result '.... Hint: Some lines were ellipsized, use -l to show in full. Regards, Adel