Why you can display and call a (not so) private method in Java and .Net

Question

In Java and C #, you can call a private method through reflection (as shown below).

• Why is this allowed?
• What are the consequences of this?
• Should it be selected in a future version of the language?
• Do other languages ​​/ platforms allow? If I have this class in Java and C #

Here is an example

public class Foo
{
    private void say() { WriteToConsoleMethod("Hello reflected world"); }
}

where WriteToConsole()depends on the language, then I can run the following to call the private method say():

FROM#

Foo f = new Foo();
var fooType = f.GetType();
var mi = fooType.GetMethod("say", BindingFlags.NonPublic | BindingFlags.Instance);
mi.Invoke(f, null);

Java

Foo f = new Foo();
Method method = f.getClass().getDeclaredMethod("say", null);
method.setAccessible(true);
method.invoke(f, null);

As you can see, this is not obvious, but it is also not difficult.

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