For that to be possible, either you had to cast from mutable to immutable (which you shouldn't have) or the mutable string derives from the immutable string (which it shouldn't have). The latter ...

I have previously blogged on how Groovy and ActionScript provide demonstrations of switching on Strings functionality that has not been available in Java. JDK 7 changes this for Java by ...

Immutable objects are highly desirable . Because an immutable object's state cannot be changed, they are particularly useful in concurrent environments . Immutable options can simplify code and ...