How can I create a new thread only if no other threads are currently open?

Question

This code creates and starts a thread:

new Thread() {
    @Override
    public void run() {
        try { player.play(); }
        catch ( Exception e ) { Sy         


        

Answer 1

You can create an ExecutorService that only allows a single thread with the Executors.newSingleThreadExecutor method. Once you get the single thread executor, you can call execute with a Runnable parameter:

Executor executor = Executors.newSingleThreadExecutor();
executor.execute(new Runnable() { public void run() { /* do something */ } });