Illegal modifier for the method name; only public, protected, private, abstract, static, final, synchronized, native & strictfp are permitted
Illegal modifier method name; allow only public, protected, private, abstract, static, final, synchronized, native and strictfp
A, public
The method of cross-package structure can call public class object
For cross-package calls, non-public modified method is not visible.
The method sex() from the type PublicUtilTest is not visible
Translation: PublicUtilTest type of process Sex () not visible
public method can be modified cross-package call.
二、protected
Non-public class can not be inherited in the other packages
PublicUtilA cannot be resolved to a type
Translation: PublicUtilA can not be resolved to a certain type
protected inheritance across package
The method PublicA.description() does not override the inherited method from PublicUtilTest since it is private to a different package
Translation: PublicA.description () method does not override inherited methods PublicUtilTest in, because it is private from different packages
Inherit inheritable permissions package and above method with a bag.
Three, private
Private methods modified if private, is not called, there will be a warning. Does not affect the use, but try to avoid never used methods and variables appear to reduce code redundancy.
The method speak() from the type PublicUtilTest is never used locally
译：PublicUtilTest类型的方法speak()从不在本地使用
private只能在本类其他方法中被调用，无法由对象实例直接调用。
通过Change visibility of 'speak()' to 'package'后会变成无修饰符方法 void speak()，可实现对象实例调用，但仅限于本包内，包权限的方法没有修饰符如PublicUtilA.description()。
四、