linux java连接x window 问题

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

Exception in thread "main" java.lang.InternalError: Can't connect to X11 window server using ':0.0' as the value of the DISPLAY variable.
        at sun.awt.X11GraphicsEnvironment.initDisplay(Native Method)
        at sun.awt.X11GraphicsEnvironment.<clinit>(X11GraphicsEnvironment.java:134)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:141)
        at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:62)
        at java.awt.Window.init(Window.java:231)
        at java.awt.Window.<init>(Window.java:275)
        at java.awt.Frame.<init>(Frame.java:401)
        at java.awt.Frame.<init>(Frame.java:366)
        at javax.swing.JFrame.<init>(JFrame.java:154)
        at com.necst.webapfw.onlineclient.GUIMain.<init>(GUIMain.java:280)
        at com.necst.webapfw.onlineclient.GUIMain.main(GUIMain.java:759)
InstallService is failed
 

在root下运行xhost ＋， 禁止xhost。