I have set setKeepAlive() before the connect-method connects to the server.
Surprisingly, on the one hand, a ACK-Flag hasn't been set by invoking the method.
Now, I get the exception below:
So, the client gets the message from the server, which the Client has send.
Then, I think, the client trys to reconnect to the server, but it isn't possible, because the client has closed its InputStreams and OutputStreams.
On the other hand, this exception tells me, that the client trys to get a "keepAlive"-Connection to the server.
So, i have to figure out how to close the Streams in the right moments.
by now, my code looks like this: