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。