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?

Schematize

is it a spring boot project ? in spring boot, by default the src/main/resources/templates is the place where views live and not the webapps folder. please post the pom.xml – Chimere

My files are in the right location. I only tried to move them when I noticed the hotswapping was not working. I returned the files to their original location after realising I could not keep the "webapps" folder. – Schematize

Good video how it works in IDEA: youtube.com/watch?v=VWF7vCJSqrA – Electuary

Possible duplicate of spring boot hotswap with Intellij IDE – Hoenir

But after these two steps the ide is compiling even when I am not editing any files . – Aliquot

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.

Zilvia

On Windows: Press Ctrl-Alt-Shift-/ and select "Registry" from the menu that appears. – Tatary

Pretty nice. For me the ultimate solution would be that the webserver restart only happens when I save a source file, not automatically. Investigating this. – Bevis

Have a look at the devtools docs. I believe there's an option for that. – Zilvia

For the current version of IntelliJ it is : Ctrl+Shift+A and write Registry – Kinnon

sadly this does not work if you use webpack and watch. in this case you have to go into the bundle.js file and edit it manually (i.e. by adding blanks somewhere) all the time ... – Declivity

PS I am using the File Watchers Plugin now (using checksum as binary). This helps, but you still need to set focus to InteliJ in case you edit the js files in some other editor. – Declivity

I am not seeing compiler.automake.allow.when.app.running in registry. I am using intellij community edition 2018.1. please help – Desimone

in addition to Patrick Grimard's answer: You need to restart IDEA! – Jargon

@Desimone you can find this option in: File --> Settings --> Advanced Settings. Enable the checkbox: "Allow auto-make to start even if developed application is currently running" in Compiler section – Sheers

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.

Tatary

I think it was renamed to "Build project automatically". I finally managed to solve this by following the instructions here: #40057557 – Lancastrian

Answer 3

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

Runnel

This does not seem to work on application.properites changes. Is this solution suppose to work on static file as well? – Intelsat

Yes, this solution works as intended. It works with changes to static files and even when changing the configuration properties file. The only difference with the accepted answer is that the option (compiler.automake.allow.when.app.running) is now available through the interface in modern versions of the IDE. – Katzenjammer

Answer 4

On Linux, press:

Ctrl-Alt-Shift-/

Ursula

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.

Carcassonne

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..

Francium

Answer 7

The option is now in Advanced settings:

Mccreery

This seems to be a duplicate of this other answer but with less informations – Lavinalavine