绘制完成后尝试调用此方法:

Try calling this method when you are done drawing:

 Toolkit.getDefaultToolkit().sync();

这会刷新某些系统(如 Linux)使用的图形缓冲区.请参阅 Javadoc:http://docs.oracle.com/javase/7/docs/api/java/awt/Toolkit.html#sync()

This flushs the graphics buffer which some systems like Linux use. See the Javadoc: http://docs.oracle.com/javase/7/docs/api/java/awt/Toolkit.html#sync()