On every "save" NetBeans deploys your application behind the scenes in milliseconds. This works well with standard NetBeans Java EE projects (ant based), or with maven 3. Maven 3 projects can be also deployed in the "on save" fashion incrementally.You only have to "Run" your application instead of "Clean and Build" or "Deploy" it. After an initial "Run" (right mouse click on project, then choose "Run") just saving a file causes an incremental redeployment of the application. It works in most of the cases, but sometimes you will have to "Clean and Build" your project. "Clean and Build" causes a recompilation and redeployment of the whole application - it is also fast (but application size dependent) and takes a few seconds.
Classic Java EE 7 Workshops: Bootstrap, Effective and Architectures, July, 13th-15th
Online workshop: Java EE 7 Bootstrap