Thread-safe is used to describe a Java class that is ready to be accessed by multiple threads without causing deadlock and/or broken state. Here I am referring to how to make an entire application especially a Swing application thread-safe.

It is well known that Swing employs single-thread model. Swing components are desired to be accessed one thread a time. And the event-dispatching thread is preferred. Here is a classic article about multi-threading in Swing (http://java.sun.com/products/jfc/tsc/articles/threads/threads1.html)

In the past months, I have been working on a Swing client application. I call it my application thereafter. My application is an IDE plug-in that needs to use multiple back-end servers. So there are a lot of remote accesses. The requirement on concurrency includes: 

1. Whenever a lengthy task e.g. accessing remote server or parsing large XML is running, the rest of my application must be available for user to use.

2. Multiple ongoing tasks are common.

3. Each ongoing task must display running indicator and progress information to user.

4. Each ongoing task must allow user to abort the task.

5. All lengthy tasks should have a configurable timeout parameter to prevent running forever when a user is not around.

Eventually I have completed my application. And as a result, I have worked out some principles, programming techniques, and utilities for developing a thread-safe Swing application. I am going to share them in the coming posts.