Class Structure View

The Class Structure View shows a tree representation of the methods in your class. Each method in the tree can be selected by clicking over it.
If a Method has a red star

on the right side of it, then that method is the Main Method.

If the method is a constructor, then the generated code will include a public static void main(String []args) method and the Constructor method will be called.
If the method is not a constructor, then the generated code will include a public static void main(String []args) method, a Constructor will be called (if present), and finally the selected method will be called.
If no method is declared a "Main Method", then the generated code will not include the public static void main(String []args) method.

You can make a method the Main Method by selecting "Main Method" from the Method menu.
Methods can be added/deleted by selecting "Add"/"Delete" from the Method menu.
Note: For applications you must set a method to be a Main Method or nothing will appear when you execute your code.