Graphical user oracle tips no protocol specified

Normal root user xhost +, xclock display a graphical interface,

The graphical user oracle tips no protocol specified  

 Approach is: oracle user xshell log in directly, do not root switch over.

Connecting to 192.168.56.131:22...
Connection established.
To escape to local shell, press 'Ctrl+Alt+]'.

/usr/bin/xauth:  creating new authority file /home/oracle/.Xauthority
[oracle@hdp-03 ~]$ xhost +
access control disabled, clients can connect from any host
[oracle@hdp-03 ~]$ cd /opt/database/
[oracle@hdp-03 database]$ ls
install  response  rpm  runInstaller  sshsetup  stage  welcome.html
[oracle@hdp-03 database]$ env|grep DISPLAY
DISPLAY=localhost:10.0
[oracle@hdp-03 database]$ xhost +
access control disabled, clients can connect from any host