tato_uy,
Can you please provide us additional information to understand the issue?
1. Can you please clarify if you are building the struts project in MyEclipse or imported the project from elsewhere ?
2. For hot deployment to work, the server has to be started in Debug mode and the project should be deployed in Exploded mode. Can you please clarify if you are doing the same?
3. Can you please create a simple web project, add a java class to it, deploy to JBoss and check if the java changes are being reflected ?
4. Can you check the actual time stamp on the .class file in the deploy location and make sure it is changing, if it is, then the problem is that JBoss is not reloading your changes.
Let us know how it works for you.