在linux系统中用Oracle帐号执行DBCA或其他JAVA图形界面程序时，报错：

Xlib: connection to ":0.0" refused by server
Xlib: No protocol specified
Error: Can't open display: :0.0

解决办法：

用root登陆，在#提示符后输入：

xhost local:oracle non-network local connections being added to access control list

敲回车运行后出现：

non-network local connections being added to access control list
xhost: bad hostname "non-network"
xhost: bad hostname "local"
xhost: bad hostname "connections"
xhost: bad hostname "being"
xhost: bad hostname "added"
xhost: bad hostname "to"
xhost: bad hostname "access"
xhost: bad hostname "control"
xhost: bad hostname "list"

此时再 su - oracle 切换到Oracle用户执行图形界面任务就可以了

man xhost中有这样一段

A complete name has the syntax ‘‘family:name’’ where the families are as follows:
inet Internet host (IPv4)
inet6 Internet host (IPv6)
dnet DECnet host
nis Secure RPC network name
krb Kerberos V5 principal
local contains only one name, the empty string
si Server Interpreted

其中local那个是用来解决同一台机器的不同用户访问X的问题的。