Master Java Servlet Inheritance with IntelliJ IDEA Diagrams

Recently I had some free time and revisited servlet knowledge. Using IntelliJ IDEA's diagram feature makes the inheritance hierarchy clear and extremely useful, so I share the steps here.

1. View inheritance diagram

In the class editor tab, right‑click and choose Diagrams → Show Diagram (or Show Diagram… for a floating window). You can also right‑click the class in the project tree and select the same option.

After opening the diagram you will see the full inheritance graph, for example with a custom Servlet class.

2. Optimize the diagram

2.1 Remove irrelevant classes

Delete classes you don't care about (e.g., Object, Serializable) by selecting them and pressing Delete. The cleaned diagram looks like:

2.2 Show class details

Right‑click the diagram and choose Show Categories to expand attributes, methods, constructors, etc., or use the toolbar button.

You can also filter by visibility (e.g., show only protected and higher) via Change Visibility Level .

2.3 Zoom in

Press Alt to activate a magnifier for a closer view.

2.4 Add other classes

Right‑click the diagram, choose Add Class to Diagram , and type the class name to include it.

For example, adding a Student class shows no arrows because it has no inheritance relationship with the displayed classes.

2.5 View source code

Double‑click a class in the diagram, then in the method list right‑click and select Jump to Source . You can also open the Structure view to navigate methods quickly.

3. Conclusion

Using these IntelliJ IDEA features makes exploring class relationships and framework source code much more comfortable.