錯誤資訊如下：

Xlib: connection to ":0.0" refused by server
Xlib: No protocol specified

解決辦法：

在linux系統中用Oracle帳號執行DBCA或其他JAVA圖形介面程式時，報錯：

Xlib: connection to ":0.0" refused by server
Xlib: No protocol specified

Error: Can't open display: :0.0

解決辦法：用root登陸，在#提示符後輸入：

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

敲回車執行後出現：

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"

此時再 su - oracle 切換到Oracle使用者執行圖形介面任務就可以了

man xhost中有這樣一段

       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那個是用來解決同一臺機器的不同使用者訪問X的問題的。