JAVA错误：Exception in thread "main" java.lang.NullPointerException

JAVA错误：Exception in thread "main" java.lang.NullPointerException
例如：

Exception in thread "main" java.lang.NullPointerException
at javax.swing.ImageIcon.<init>(Unknown Source)
at chuangti.Example1.CreateJFrame(Example1.java:41)
at chuangti.Example1.main(Example1.java:84)

解答　

java.lang.NullPointerException //即指针指向为空
at javax.swing.ImageIcon.<init>(Unknown Source)	//为空的区域
at chuangti.Example1.CreateJFrame(Example1.java:41) //41行
at chuangti.Example1.main(Example1.java:84)	//84行