Multiple Event Dispatch Threads

I am new to Java Swing 开发者_如何学Cand my question is related to Event Queues and Dispatch threads.

I read that it is possible to have multiple event queues , each per AppContext instance. Similarly does it mean each AppContext Event queue has its own event dispatch thread.

It is only possible to have one event dispatch thread as far as I'm aware.

Apparently AppContext is not meant to be used by developers, although I'm not really familiar with it.

1) basically you only needed to know if your code will be done on EDT (all changes must be done on EDT),

2) if you have any doubts, it is possible to test

if (EventQueue.isDispatchThread()) {

or (that's same and returns true if is on EDT)

if (SwingUtilities.isEventDispatchThread()) {

more here or here

3) all output from Background tasks must be wrapped into invokeLater(), basic stuff about Concurency in Swing