Interpolator vs MessageFormat

[nimo22]

I have red this:

MessagesAndPlaceHolders

I have used the interpolater:

String a = Interpolator.instance().interpolate("#{messages['myGreetings']}", "john");

My properties-file has the key 'myGreetings':

myGreetings = hello {0}

But this does not work, my message get not resolved,
The output is:

hello {0} instead of hello john.

When I use this, it works:

String t= SeamResourceBundle.getBundle().getString("myGreetings");
String resolved = MessageFormat.format(t, "john");

The output is:

hello john. The variable {0} is resolved successfully.

So, what is wrong with my Interpolator ???