Creating a Java class

Once we have created a new project, we should see the Projects, Files, and Services tabs like I have in the following image. Let's look at the Files tab. Whereas the Projects tab is a bit of an abstraction, the Files tab shows us what's actually contained within the filesystem where our HelloWorld project lives:

Most importantly, you'll see that the src file here has no files in it. That's because there's no source code associated with our project, so right now it won't do anything. To remedy this, right-click on src, choose New, and then Java Class...:

We're going to name our Java Class HelloWorld, just like the name of the project because it is our main class where the program should be entered and start from. Everything else is going to work just fine here for now, so click on Finish and NetBeans will create HelloWorld.java for us. A .java file is essentially a text file, but it should only contain Java code and comments: