This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Boot 3.3.4!spring-doc.cn

This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Boot 3.3.4!spring-doc.cn

To run your application without first building an archive use the bootRun task:spring-doc.cn

$ ./gradlew bootRun

The bootRun task is an instance of BootRun which is a JavaExec subclass. As such, all of the usual configuration options for executing a Java process in Gradle are available to you. The task is automatically configured to use the runtime classpath of the main source set.spring-doc.cn

By default, the main class will be configured automatically by looking for a class with a public static void main(String[]) method in the main source set’s output.spring-doc.cn

The main class can also be configured explicitly using the task’s main property:spring-doc.cn

tasks.named("bootRun") {
	mainClass = 'com.example.ExampleApplication'
}
tasks.named<BootRun>("bootRun") {
	mainClass.set("com.example.ExampleApplication")
}

Alternatively, the main class name can be configured project-wide using the mainClass property of the Spring Boot DSL:spring-doc.cn

springBoot {
	mainClass = 'com.example.ExampleApplication'
}
springBoot {
	mainClass.set("com.example.ExampleApplication")
}

By default, bootRun will configure the JVM to optimize its launch for faster startup during development. This behavior can be disabled by using the optimizedLaunch property, as shown in the following example:spring-doc.cn

tasks.named("bootRun") {
	optimizedLaunch = false
}
tasks.named<BootRun>("bootRun") {
	optimizedLaunch.set(false)
}

If the application plugin has been applied, its mainClass property must be configured and can be used for the same purpose:spring-doc.cn

application {
	mainClass = 'com.example.ExampleApplication'
}
application {
	mainClass.set("com.example.ExampleApplication")
}

Passing Arguments to Your Application

Like all JavaExec tasks, arguments can be passed into bootRun from the command line using --args='<arguments>' when using Gradle 4.9 or later. For example, to run your application with a profile named dev active the following command can be used:spring-doc.cn

$ ./gradlew bootRun --args='--spring.profiles.active=dev'

See the javadoc for JavaExec.setArgsString for further details.spring-doc.cn

Passing System Properties to Your application

Since bootRun is a standard JavaExec task, system properties can be passed to the application’s JVM by specifying them in the build script. To make that value of a system property to be configurable set its value using a project property. To allow a project property to be optional, reference it using findProperty. Doing so also allows a default value to be provided using the ?: Elvis operator, as shown in the following example:spring-doc.cn

tasks.named("bootRun") {
	systemProperty 'com.example.property', findProperty('example') ?: 'default'
}
tasks.named<BootRun>("bootRun") {
	systemProperty("com.example.property", findProperty("example") ?: "default")
}

The preceding example sets that com.example.property system property to the value of the example project property. If the example project property has not been set, the value of the system property will be default.spring-doc.cn

Gradle allows project properties to be set in a variety of ways, including on the command line using the -P flag, as shown in the following example:spring-doc.cn

$ ./gradlew bootRun -Pexample=custom

The preceding example sets the value of the example project property to custom. bootRun will then use this as the value of the com.example.property system property.spring-doc.cn

Reloading Resources

If devtools has been added to your project it will automatically monitor your application’s classpath for changes. Note that modified files need to be recompiled for the classpath to update in order to trigger reloading with devtools. For more details on using devtools, refer to this section of the reference documentation.spring-doc.cn

Alternatively, you can configure bootRun such that your application’s static resources are loaded from their source location:spring-doc.cn

tasks.named("bootRun") {
	sourceResources sourceSets.main
}
tasks.named<BootRun>("bootRun") {
	sourceResources(sourceSets["main"])
}

This makes them reloadable in the live application which can be helpful at development time.spring-doc.cn

Using a Test Main Class

In addition to bootRun a bootTestRun task is also registered. Like bootRun, bootTestRun is an instance of BootRun but it’s configured to use a main class found in the output of the test source set rather than the main source set. It also uses the test source set’s runtime classpath rather than the main source set’s runtime classpath. As bootTestRun is an instance of BootRun, all of the configuration options described above for bootRun can also be used with bootTestRun.spring-doc.cn