javac has longstanding behavior, apparently unspecified, to reject
accessibility modifiers on classes nested within an anonymous or local class.
The changes involved in supporting statics inside of local classes have drawn
attention to this behavior.
void m() {
class Local {
private class C1 {} // error
class C2 {}
protected class C3 {} // error
public class C4 {} // error
class Inner {
private class D1 {} // error
class D2 {}
protected class D3 {} // error
public class D4 {} // error
}
}
}
There's nothing in 8.1.1, 14.3, 15.9.5, or 8.5 to suggest this behavior.
(There's a rule about modifiers on a local class declaration itself, but
nothing about its members.)
In practice, members of local classes are essentially private anyway—there is
no way to refer to them outside of the local class's enclosing method. So the
access modifiers don't seem that useful. But they do affect things like
inheritance (local class B extends local class A) and reflection. And while
this same argument applies to fields, javac allows unrestricted use of field
access modifiers inside local classes.
I think the appropriate resolution is to treat this as a javac bug and remove
the access modifier restriction. Any reasons not to do so?
