This week's book giveaway is in the Other Languages forum. We're giving away four copies of Functional Reactive Programming and have Stephen Blackheath and Anthony Jones on-line! See this thread for details.
If you meant dynamic type binding for variables then no Java does not support it. Java variable type is statically bound during the variable declaration. Dynamic type binding is supported on other languages such as Lisp, where variable type is bound when it is assigned a value.