When you create your project, you can create a development WAR.
If you create a development WAR, you are asked whether to publish it.
While most application servers dynamically publish WAR files, some do not. Consult the documentation for your application server to find out if automatic publishing of WAR files is supported. If not, you need to manually publish the development WAR each time you make changes to your project.
IBM® WebSphere® Application Server supports automatic publishing.
Parent topic: Creating a server configuration: wpf7