20. Developer tools

Spring Boot includes an additional set of tools that can make the application development experience a little more pleasant. The spring-boot-devtools module can be included in any project to provide additional development-time features. To include devtools support, simply add the module dependency to your build:

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")
}

Note

Developer tools are automatically disabled when running a fully packaged application. If your application is launched using java -jar or if it’s started using a special classloader, then it is considered a “production application”. Flagging the dependency as optional is a best practice that prevents devtools from being transitively applied to other modules using your project. Gradle does not support optional dependencies out-of-the-box so you may want to have a look to the propdeps-plugin in the meantime.

	Tip
If you want to ensure that devtools is never included in a production build, you can use the excludeDevtools build property to completely remove the JAR. The property is supported with both the Maven and Gradle plugins.