Java threading question (easy mode I'd think)

[KevySaysBeNice]

Here is the scenario brothers and sisters:

We have a simple program that has a basic GUI interface with a few buttons.

We have a button, then when clicked, activates and RFID tag reader in a separate thread so that we can continue to click the buttons in the GUI while the RFID tag reader is doing its THANG. SHAKE THAT BOOTY RFID TAG READER THREAD.

Anyway, here is the thing:

We want to be able to get the RFID tag that is read into the main thread however we are stumbling, so to speak. We can get the RFID tag by calling a function of the RFID thread, however that would require us doing it manually.

Instead, we want the RFID thread to call a function in the main thread when a new tag is read, if that makes sense. The idea would be, when a new tag is encountered we'd want the GUI to update accordingly but we don't want to lock up the main GUI thread by manually polling the RFID tag thread.

Sorry for possibly not making that much sense, but thanks for the help!

 

[kschneid]

There are a number of general approaches you can take. If you're using Java 6, SwingWorker is now a part of javax.swing. Otherwise, you can use the backport or just EventQueue.invokeLater. Here's a tutorial lesson that might be of interest.

 

[ambientZ]

If you just want the other thread to update the gui, pass a reference to the gui object you want it to be able to update into the constructor of that other thread. Then it can access the gui component directly.

Of course swing isn't thread safe and from said other thread you should use the invokelater functionality later that the previous poster mentioned.