Spring boot devtools - Static content reloading does not work in IntelliJ

Question

When building my first Spring Boot app, I discovered that I need to restart my app every time I make a change to a Javascript file in /resources/static/some-file.js

This is very time consuming.

When I move the files to the /webapps/ folder, it works as expected, but the files are not packaged in a JAR. The docs mention this, so I cannot continue this way.

I read all about spring-boot-devtools , and have installed it in my POM, but the hotswapping doesn't seam to be working. I still need to restart the entire app to see a Javascript or CSS file change.

When the app starts, I can see the line LiveReload server is running on port 35729 , so spring-boot-devtools must be doing something...

What would be the steps to further investigate what is going wrong?

My guess is that when IntelliJ runs the app, the files are copied, so when I make a change, I'm actually changing the original files and not the ones used by the running app.

PS: I'm using Maven, IntelliJ IDEA 15 and Spring Boot 1.3.3 with the embedded Tomcat server. I'm not sure what command IntelliJ runs to start the app. The IDE is handling this "automatically". Perhaps I need to change my run configuration?

Answer 1

You need to turn on a couple of features in IntelliJ to make this work.

First, there's a project specific setting which you would need to apply on any project you want to use devtools in. Go to Preferences > Compiler and enable "Make project automatically."

The next setting is an IDEA registry setting that applies to all projects.

• In macOS (OSX), press Shift+Command+A ( Shift+Ctrl+A in Windows)
• Type "Registry" in the search box that appears, and select the registry to open it.
• Lookup compiler.automake.allow.when.app.running and enable it.

After that, restart your app. You will notice that the project keeps rebuilding with every change you make. When you check out the result in the browser, you will see both static files and code have been updated.

Answer 2

For Windows users the steps are:
1) Go to File->Settings, then to "Build,Execution,Deployment"->Compiler and enable the "Make project automatically" flag.
2) Press Ctrl-Alt-Shift-/ and select "Registry" from the menu that appears. Enable compiler.automake.allow.when.app.running flag.
3) Start/restart the app and observe static content reloading.

Answer 3

On Linux, press:

Ctrl - Alt - Shift - /

Answer 4

For IntelliJ 2021.2 version or above below are steps that you need to follow

1. Add spring-boot-devtools dependency if not already added.

2. Enable Build project automatically as shown below

3. Enable option in Advanced Settings as shown below

Answer 5

For mac users I had to press Command + Shift + A

And restart INTELLIJ after Step1 and Step2 without which the registry option was not appearing.

Answer 6

You can user like bellow:

1. First Open Preferences.../Settings... -> Build, Execution, Deployment -> Compiler and allow Build project automatically. Image will look like

2. Second , we change Registry configuration. Press command+shift+A for macOS or if you are using Windows press Ctrl+Shift+A , and search for Registry. enable compiler.automake.allow.when.app.running .Images look like bellow

Registry image look like..

compiler.automake.allow.when.app.running enable image look like

Then Enjoy..

Answer 7

The option is now in Advanced settings: