在CENTOS4.4上运行AWT程序出现以下异常：
Exception in thread "main" java.awt.HeadlessException:
No X11 DISPLAY variable was set, but this program performed an operation which requires it.
at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:159)
at java.awt.Window.(Window.java:431)
GOOGLE了一下，有不少解决方案，但是我的虚拟机只安装了命令行，请问该如何运行AWT程序，是不是必须安装图形界面，才可以运行AWT程序
