int is a primitive data type,whereas String is an object.A cast from a primitive to an object does not make sense.Inorder to perform conversions like this,
java provides a wonderful set of classes called wrapper classes.The wrapper class objects wraps around primitives to make them behave similar to objects.The conversion you tried can be done like this....
Hope this helps...
SCJP 1.4
Do not dwell in the past, do not dream of the future, concentrate the mind on the present moment.