spring boot hotswap with Intellij IDE

Question

I have a spring boot application running fine with Intellij IDE. i.e i started the Application class that has the main method which delegates to SpringApplication.run. Everything works great except hotswap. When I change the source, I am forced to re-start the application. Even If I start the application in debug mode, I dont see hotswap working. I could see that Intellij's Debug settings have hotswap enabled.

My observation shows that when I run the springboot application, classpath used is my

/projects/MyProject/classes/production/....

Files under classes/production are not getting updated when I change the code. Intellij IDE compiles the files but does not update classes/production directory. How do I get hotswap working with IntelliJ IDE for spring-boot?

Answer 1

A solution that uses devTools works :

1 - Adding devtools to your project

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-devtools</artifactId>
</dependency>

2 - Enabling automatic build

Open the Settings --> Build-Execution-Deployment --> Compiler and enable :

Build Project Automatically.

3 - Update the value of compiler.automake.allow.when.app.running

press ctrl+shift+A and search for the registry. In the registry, enable :

compiler.automake.allow.when.app.running

---

References :

• https://dzone.com/articles/spring-boot-application-live-reload-hot-swap-with

Answer 2

Found out the root cause. This has nothing to do with Spring-boot. On changing my groovy source files, files were not auto-compiled.

To recompile changed files and swap them:

• Ctrl+Shift+F9 on Windows
• Cmd+Shift+F9 on Mac

Answer 3

Step 1: Add developer tools denpendency

Maven.

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <optional>true</optional>
    </dependency>
</dependencies>

Gradle.

dependencies {
    compile("org.springframework.boot:spring-boot-devtools")
}

Step 2: Go to File | Settings | Build, Execution, Deployment | Compiler

enable Build project automatically & Apply & OK

Step 3: Press shortcut key Ctrl+Shift+A & Search Registry keyword & Press Enter

Enable complier.automake.allow.when.app.running & Click Close Button

Step 4: Disable cache on your favorite web browser

Step 5: Done!!!

Watch Solution On YouTube

Answer 4

In my case even after adding the Spring Boot dev tools and checking the build project automatically, it was not working. What was missing was this:

1. Go to the project run configuration.

2. Set on'Update' action and 'On frame deactivation' both to 'Update classes and resources'. And it worked like a charm.

Answer 5

Use spring-loaded. It works fine with bean reloading. It's free alternative to JRebel.

Another way is to use DCEVM or hotswapagent

Answer 6

I noticed the same problem as well. I am on the Intellij 13.1.1. and for it to hotswap the changed class. I have to run the app in debug mode, then after changing the class, select "Run->Reload Changed Classes" manually.

I also have the debugger set to hotswap as indicated in http://www.jetbrains.com/idea/webhelp/reloading-classes.html but doesn't seem to work.

Anyway, at least the manual "Run->Reload Changed Classes" menu works.

Answer 7

@Sameer Khanal's answer worked but since so much time has passed, I offer some clarification

1. Install the spring boot devtools dependencies (https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-devtools)

2. Modify your run option

3. Update the options for On 'Update' action and On frame deactivation like so:

4. Click on OK and you are done

Hope that helps

Answer 8

For multiple changes, use "Compile And Reload File"(Add "spring-boot-devtools" first). Double click "Shift" to show the diagram in Mac.

Or try spring-loaded which I haven't tried yet. But seems it could work.

Answer 9

Add the deployment artifact exploded, in the deployment tab, this did the trick for me.

Answer 10

You can use either of the following methods to auto reload Thymeleaf templates:

1. Spring Boot Dev Tools
2. Change Thymeleaf Templates Path
3. Gulp Watch

I recommend Gulp watch as it is easier to setup and works great:

var gulp = require('gulp'), 
watch = require('gulp-watch');

gulp.task('watch', function () {
    return watch('src/main/resources/**/*.*', () => {
            gulp.src('src/main/resources/**')
                //replace with build/resources/main/ for netBeans
                .pipe(gulp.dest('out/production/resources/')); 
    });
});

gulp.task('default', ['watch']);

Now enter the following command in your terminal to start gulp watch:

$ gulp 
//OR
$ gulp watch

I wrote a blog post on auto reloading Thymeleaf templates without restart in IntelliJ IDE.