为什么不能保护java主类? [英] Why can't java main class be protected?
问题描述
我可以创建具有Access说明符public或默认值的Main类。
I can create Main class with Access specifier "public" or default.
但为什么我不能使用protected创建。默认情况下允许为什么不受保护。
But why can't I create with protected. As default itself allowed why not protected.
公开:
public class MainClass {
public static void main(String[] args) {
}
}
默认值:
class MainClass {
public static void main(String[] args) {
}
}
受保护:
protected class MainClass {
public static void main(String[] args) {
}
}
显示错误:
类MainClass的非法修饰符;只有公共的,抽象的和final是允许的MainClass.java SCJP / src第1行Java问题
Its showing error: Illegal modifier for the class MainClass; only public, abstract & final are permitted MainClass.java SCJP/src line 1 Java Problem
推荐答案
protected
涉及向成员提供包含类型访问权限的子类。这里没有包含类型,那是什么意思?
protected
relates to giving subclasses of the containing type access to a member. There's no containing type here, so what would it mean?
请注意,这与 main
无关这样......它适用于任何顶级课程。它的 对于要保护的嵌套类型有效:
Note that this has nothing to do with main
as such... it applies to any top-level class. It is valid for a nested type to be protected though:
public class Foo {
protected static class Bar{}
}
这允许 Foo
访问 Bar
。
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