Some Notes On Java Access Modifiers: Public Protected, Default And Private

The following table can, in general, distinct access modifiers clearly.

Modifier    | Class | Package | Subclass | Other package
public      |  y    |    y    |    y     |   y
protected   |  y    |    y    |    y     |   n
default     |  y    |    y    |    n     |   n
private     |  y    |    n    |    n     |   n

y: accessible
n: not accessible

But there are some details that have to be noted down.

#1

A normal class has only two modifiers, namely, 'public' and 'default' (no modifier), which is obvious in semantics that a private or protected class is not congruent with the meaning of the above table. Whereas inner class can be defined by all the four modifiers.

#2

It is probably worth pointing out that in the case of 'default' (no modifier), whether or not the subclass can see it's superclass's methods/fields depends on the location of the subclass. If the subclass is in another package, then the answer is it can't. If the subclass is in the same package then it CAN access the superclass methods/fields.

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