Run Thread in JavafX Service - multithreading

Question

I'm confused about how to continue writing my program.
Basically, it connects to multiple serial devices, and then updates the javafX Application based on the responses from the devices (I first have to send the machine a message). So what I did was create a thread to run in the service thread, so that my program would not freeze and the Thread could pause until the message is read (there's a delay between sending and receiving a message over the serial device).
service = new Service() {
#Override
protected Task<String> createTask() {
return new Task<String>(){
#Override
protected String call() throws Exception {
new Thread(thread).start();
return null;
}
};
}
};
Where the thread does some loop, continuously sending and reading messages.
#Override
public synchronized void run() {
while(serialOn && isRunning){
sendMessages();
}
}
public synchronized void sendMessages(){
sendSerial1();
this.wait();
sendSerial2();
this.wait();
}
public synchronized void readMessage1(){ // same readMessage2 for the sendSerial2()
getMessage(); // updates variables that are bound to the Javafx App
this.notify();
}
But, I think the service finishes (i.e. succeeds or fails) before it event starts my serial thread. But I want the service to continue running while the program sends and receives messages.
Let me know if you need more code, it's a little long and requires the serial devices to run, but I can include it here if it makes the question easier to understand.

Answer 1

Don't create a new thread in the call() method of the service's Task.
A service automatically creates threads on which the call() will be invoked. If you want control over the thread creation and use, then you can (optionally) supply an executor to the service (though in your case you probably don't need to do that unless you don't want the service to be a daemon thread).
From the Service javadoc:
If an Executor is specified on the Service, then it will be used to actually execute the service. Otherwise, a daemon thread will be created and executed.
So shift the code inside the run() method of your Runnable and put it into the call() method of the Task for the Service (the Task itself is a Callable, which is a Runnable, so having an additional Runnable is both redundant and confusing).