IntelliJ IDEA 社区版和 Spring 使用 Spring DevTools 重新加载缓慢

Question

I know IDEA CE doesn't have support for Spring, but I still can develop with decent support for autocompletion, which is enough for me.

The issue I have is that it takes 5 to 7 seconds for the IDE to reload the server with the changes I made after hitting Ctrl + S. So, I searched for more options I can modify, and I tried these:

But it doesn't solve the issue.

While I know I can use VSCode since the Java support is excellent and with Spring the reload is very fast, for Kotlin support there is no extension good enough. So I'd like to find a fix to reduce the delay of the server restart, if possible. It seems to be done on purpose to force you to buy the Professional edition.

Answer 1

You don't need to use automatic compilation or DevTools for IntelliJ IDEA Community or Ultimate to hotswap classes in Debug mode. If you want to compile on Ctrl + S , assign this shortcut to Build | Build Project action (Settings (Preferences on macOS) | Keymap | Main Menu | Build | Build Project, right click, Add Keyboard Shortcut ).

IDE will hotswap the changed classes and the changes will be available in the browser in less than a second:

Sample project: boot-hotswap-demo.zip .

Steps:

1. Click Debug button to start the app
2. Open http://localhost:8080/ in the web browser
3. Observe Greetings from Spring Boot!!! output
4. Change the string in HelloController.java to something else
5. Build | Build Project (or Ctrl + S if you assigned it to this action)
6. Reload the page in the browser, observe the changes in less than a second, IDE shows a notification about reloaded classes.

You can also uncomment the spring-boot-devtools dependency in pom.xml if you want to rely on the DevTools and it will trigger the server restart on changes. It's a bit slower, but certainly not 5-7 seconds as you describe.

Answer 2

We use 2 annotation processors in our project: annotationProcessor "org.springframework.boot:spring-boot-configuration-processor" and annotationProcessor "org.projectlombok:lombok".

Lombok works fine. But if spring-boot-configuration-processor is active - hot swap always reload all classes, that takes more than minute on my project, much faster to restart app completely.

I comment that processor before start when I need hot swap.