4 replies to this topic

[sharathm]

why final is been used in --> public static final System out;

in the system class

[farrell2k]

It's done like this so that you can't just simply change them. You must call setIn(), setOut(), etc, which can then validate your changes.

[Sinipull]

Actually final won't let you change it even through the setter method. It must be going around the restriction somehow. I was looking around in the Java source and managed to track the code until:

public static void setOut(PrintStream out) {
    checkIO();
    setOut0(out);
}

and then:

private static native void setOut0(PrintStream out);

i read that native keyword indicates that non-java code is being run from the method. No idea where it goes further....

[wim DC]

I suppose the final keyword is only checked at compile-time so avoidable at runtime using reflection or anything.

[farrell2k]

One of the nice things about Java is that you don't have to know why it works, just that it does. :)

[JavaSpecialists 096] - Java 5 - "final" is not final anymore - A nice read.