private protected public 区别

关于private protected 和 public 的区别与使用，在javase教程里已讲的很清楚

Access LevelsModifierClassPackageSubclassWorldpublicYYYYprotectedYYYNno modifierYYNNprivateYNNN

http://docs.oracle.com/javase/tutorial/java/javaOO/accesscontrol.html