I'm trying to run a Java application on Xubuntu 14.04, but I always get
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.access$200(X11GraphicsEnvironment.java:65)
at sun.awt.X11GraphicsEnvironment$1.run(X11GraphicsEnvironment.java:110)
at java.security.AccessController.doPrivileged(Native Method)
at sun.awt.X11GraphicsEnvironment.<clinit>(X11GraphicsEnvironment.java:74)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:190)
at java.awt.GraphicsEnvironment.createGE(GraphicsEnvironment.java:102)
at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:81)
at sun.awt.X11.XToolkit.<clinit>(XToolkit.java:119)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:190)
at java.awt.Toolkit$2.run(Toolkit.java:868)
at java.security.AccessController.doPrivileged(Native Method)
at java.awt.Toolkit.getDefaultToolkit(Toolkit.java:860)
echo $DISPLAY returns :0.0
What could be wrong here?