Downloading and Installing NetBeans IDE
These instructions describe how to download and install NetBeans, a commonly used IDE for Java programming. Using an IDE means that you have all of the tools you need in one place (your "development environment") instead of having to organize things manually. Use the instructions in Step 2 to write a simple Java program called "Hello.java" and then compile and run it.
9. Developing and Deploying Web Application in NetBeans
9.6. Debugging Web Applications in NetBeans
You can debug a webapp just like standalone application. For example, you can set breakpoints, single-step through the programs, etc.