Tests whether this key's channel is ready to accept a new socket connection.
An invocation of this method of the form k.isAcceptable() behaves in exactly the same way as the expression
k.readyOps() & OP_ACCEPT != 0
If this key's channel does not support socket-accept operations then this method always returns false.
readyOps() & OP_ACCEPT is nonzero
|If this key has been cancelled|