Question

I want to create a class, ClassB, as inner class of ClassA, but I want to write down outside ClassA.java file.

How can I do this?

It will be a lot of inner class, and ClassA.java file will be enormous.

UPDATE
What I really want to do is define ten classes that they will be only accessible by one class. All of them are defined inside the same package.

Thanks.

Answer 1

Put all your classes in a package and define the classes to be package private.

package com.example.here

class Hello{
    //...
}

Notice the absence of the keyword public? You will only be able to create an instance of the class Hello if the class creating it is in the com.example.here package.