CS2103 Software Engineering in Neovim - A Post Reflection

Now that CS2103 Software Engineering is over, is using NeoVim as a Java Editor worth it?

My answer: the learning was worth it, but the functionalities of IntelliJ totally crushed Java development. It is the killer app that you need, if you are doing serious Java development.

The Pros and Cons with NVim


Vim’s many keybindings makes text editing enjoyable. With all the familiar jumps, yanking paragraphs, search and replace - I absolutely loved the “fingers never leave the home row” experience.

With many other tools, such as fzf bindings for vim, and tim pope’s commentary.vim, surround.vim and https://github.com/wellle/targets.vim made editing a breeze.

Commenting out code is just gc<object>, and since Java has quite a bit of method chaining, using targets.vim to clear out chained function call is just di. since method calls are chained by dots.

With a usual tiling manager, like the i3 that I am using, I am able to have a workspace with a regular terminal running vim, a narrow terminal allow me to try things out in jshell or just build my project, and tiled with the built project for manual testing. Most importantly, switching between them is a breeze with the normal keybindings (self-defined, if need be)!


COC’s Java was really CPU intensive, there are many times it just hogs up the CPU and hangs the nvim instance. I am not sure where the problem is, but I would imagine in a huge project this is not feasible at all. Also when you switch between buffers, there will be some time when the language server parses the new buffer and introduces waits around 3-4 seconds, which can be quite unbearable to wait.

The Pros and Cons with IntelliJ

A friend of mine, once a Java developer, saw me developing in NVim and hence convinced me to give IntelliJ a whirl, showing me the power of the IDE itself. It certainly does not disappoint, and even taught me new things about the whole :CocAction business.


IntelliJ was the result of many, many years of development and is extremely feature rich. I recommend anyone using IntelliJ take some time to go through a course, maybe a good Video Tutorial series to learn some useful features before you start. It is a waste if you use your IntelliJ just like a Gedit with a terminal and a file explorer.

For example, upon writing a few classes in Java you realized that they share some functionalities and you would like to extract out a few functions from these classes into an Interface. IntelliJ has it. You want to delete a class and all of its occurrences. In NVim, you can delete the class, and use some command line tools like grep or rg to search for occurrences, and then delete them, which although is possible, is a lot more work. Renaming a package and have to change all the child classes’s package declaracion? You can do it with one button in IntelliJ. In CLI, you probably need some data wrangling skills, and with some sed magic and some Googling. In any case, IntelliJ was way more powerful than I realized.


As almost all IntelliJ users would complain - it is too memory-intensive. Also for such a huge IDE, you will need some time to get used to the different key bindings, such as switching between the editor and terminal, and I can’t seem to remember them because they differ with my usual ones a lot. Also auto format on save is not available out of the box and requires some keyboard macro recording. Although I would say in the long run, these would be outweighed by the benefits if you do Java programming for a living.

Final reflection

I realized that there should have been a standard translation protocol which translates Java checkstyle into a formatting standard, recognized by the IDEs. Currently users can import styleguides (not checkstyle), which might conflict with a checkstyle file. Also checkstyle file often warns for code-quality issues (such as trailing spaces, bracing, and comments), which would be good if can be integrated by the IDE/NVim. Maybe there is one which I am not aware of, but it would be really useful!

It was a long journey and I think I have discovered a bit more about NVim and Editors through this little experiment.