Cannot start tomcat7 on ubuntu 16.04 - work for tomcat7.service failed

Question

Cannot start tomcat7 on ubuntu 16.04 - work for tomcat7.service failed

I try to run tomcat7 on ubuntu 16.04, but when I execute

sudo service tomcat7 start

I get

The operation for tomcat7.service failed because the management process failed with an error code. See "Systemctl status tomcat7.service" and "journalctl -xe" for details.

when i run systemctl status tomcat7.servicei get

tomcat7.service - LSB: Launch Tomcat. Uploaded: uploaded (/etc/init.d/tomcat7; bad, vendor preset: enabled) Active: failed (Result: exit-code) from Fri 2017-04-21 22:21:52 UTC; 6 minutes ago Documents: man: systemd-sysv-generator (8) Process: 3755 ExecStart = / etc / init.d / tomcat7 start (code = exited, status = 1 / FAILURE)
Apr 21 22:21:52 mitutorweb systemd [1]: Launch LSB: Launch Tomcat ....
Apr 21 22:21:52 mitutorweb sudo [3763]: root: TTY = unknown; PWD = /; USER = root; COMMAND = / bin / nano / etc / default / tomcat7
Apr 21 22:21:52 mitutorweb sudo [3763]: pam_unix (sudo: session): the session is open to root by (uid = 0)
Apr 21 22:21:52 mitutorweb tomcat7 [3755]: Terminal opening error: unknown.
Apr 21 22:21:52 mitutorweb sudo [3763]: pam_unix (sudo: session): session is closed to root
Apr 21 22:21:52 mitutorweb systemd [1]: tomcat7.service: management process completed, code = status displayed = 1
Apr 21 22:21:52 mitutorweb systemd [1]: Could not start LSB: start Tomcat ..
Apr 21 22:21:52 mitutorweb systemd [1]: tomcat7.service: The entered state is not entered.
Apr 21 22:21:52 mitutorweb systemd [1]: tomcat7.service: 'exit-code'.