A task that returns a result and may throw an exception. Implementors define a single method with no arguments called call.

The Callable interface is similar to java.lang.Runnable, in that both are designed for classes whose instances are potentially executed by another thread. A Runnable, however, does not return a result and cannot throw a checked exception.

The Executors class contains utility methods to convert from other common forms to Callable classes.

since	1.5
V	the result type of method call
See also	java.util.concurrent.Executor