I would like to use DevTools in my Spring Boot web application. I use IntelliJ to it. But it doesn't love me and it doesn't work. I read plenty of documentation about this problem, but probably the solution escaped my attention. Maybe you can help me.
I use Gradle and Kotlin. But I think it shouldn't be a problem. What I tried:
Here is my Demo:
build.gradle.kts
import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
plugins {
id("org.springframework.boot") version "2.1.8.RELEASE"
id("io.spring.dependency-management") version "1.0.8.RELEASE"
kotlin("jvm") version "1.2.71"
kotlin("plugin.spring") version "1.2.71"
}
group = "com.example"
version = "0.0.1-SNAPSHOT"
java.sourceCompatibility = JavaVersion.VERSION_1_8
val developmentOnly by configurations.creating
configurations {
runtimeClasspath {
extendsFrom(developmentOnly)
}
}
repositories {
mavenCentral()
}
dependencies {
implementation("org.springframework.boot:spring-boot-starter-web")
implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
implementation("org.jetbrains.kotlin:kotlin-reflect")
implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
developmentOnly("org.springframework.boot:spring-boot-devtools")
testImplementation("org.springframework.boot:spring-boot-starter-test")
}
tasks.withType<KotlinCompile> {
kotlinOptions {
freeCompilerArgs = listOf("-Xjsr305=strict")
jvmTarget = "1.8"
}
}
com.excample.demo.controller.RestController.kt
package com.example.demo.controller
import org.springframework.web.bind.annotation.RequestMapping
import org.springframework.web.bind.annotation.RestController
@RestController
class RestController {
@RequestMapping("/testDevTools")
public fun testDev(): String? {
return "apple"
}
}
com.excample.demo.DemoApplication.kt
package com.example.demo
import org.springframework.boot.autoconfigure.SpringBootApplication
import org.springframework.boot.runApplication
@SpringBootApplication
class DemoApplication
fun main(args: Array<String>) {
runApplication<DemoApplication>(*args)
}
And when I start application:
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.1.8.RELEASE)
2019-09-19 15:59:15.727 INFO 6672 --- [ restartedMain] com.example.demo.DemoApplicationKt : Starting DemoApplicationKt on DESKTOP-QRT95S2 with PID 6672 (started by Baráth Péter in C:\Users\Baráth Péter\OneDrive - Sonrisa Kft\Projects\Demos\devToolsDemo)
2019-09-19 15:59:15.731 INFO 6672 --- [ restartedMain] com.example.demo.DemoApplicationKt : No active profile set, falling back to default profiles: default
2019-09-19 15:59:15.890 INFO 6672 --- [ restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : Devtools property defaults active! Set 'spring.devtools.add-properties' to 'false' to disable
2019-09-19 15:59:15.890 INFO 6672 --- [ restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : For additional web related logging consider setting the 'logging.level.web' property to 'DEBUG'
2019-09-19 15:59:19.376 INFO 6672 --- [ restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 9090 (http)
2019-09-19 15:59:19.430 INFO 6672 --- [ restartedMain] o.apache.catalina.core.StandardService : Starting service [Tomcat]
2019-09-19 15:59:19.431 INFO 6672 --- [ restartedMain] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.24]
2019-09-19 15:59:19.666 INFO 6672 --- [ restartedMain] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext
2019-09-19 15:59:19.666 INFO 6672 --- [ restartedMain] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 3776 ms
2019-09-19 15:59:20.205 INFO 6672 --- [ restartedMain] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor'
2019-09-19 15:59:20.878 WARN 6672 --- [ restartedMain] o.s.b.d.a.OptionalLiveReloadServer : Unable to start LiveReload server
2019-09-19 15:59:21.004 INFO 6672 --- [ restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 9090 (http) with context path ''
2019-09-19 15:59:21.018 INFO 6672 --- [ restartedMain] com.example.demo.DemoApplicationKt : Started DemoApplicationKt in 6.16 seconds (JVM running for 7.234)
2019-09-19 15:59:45.492 INFO 6672 --- [nio-9090-exec-3] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring DispatcherServlet 'dispatcherServlet'
2019-09-19 15:59:45.493 INFO 6672 --- [nio-9090-exec-3] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet'
2019-09-19 15:59:45.502 INFO 6672 --- [nio-9090-exec-3] o.s.web.servlet.DispatcherServlet : Completed initialization in 9 ms
It contains this line:
2019-09-19 15:59:15.890 INFO 6672 --- [ restartedMain] .e.DevToolsPropertyDefaultsPostProcessor : Devtools property defaults active! Set 'spring.devtools.add-properties' to 'false' to disable
So I don't know what is the problem. Devtools is active. I tried to change apple string in RestController. Then save and refresh the webpage and it didn't change. I am very grateful for any advice.
The setting "Build project automatically" you reference only applies to the IntelliJ's own compiler. If you delegate your build to Gradle, which is the default in newer versions of IntelliJ, it will in fact not build your project automatically.
The devtools module will only reload classes on recompilation. So you could hit the "Build Project" button whenever you are ready for a reload to trigger a build with Gradle. But as this will also run unit tests and maybe even static code analysis (if you are using that), the turn-around time would still be rather high. You could manually run the classes task with Gradle to compile only classes, but doing this manually is annoying.
Instead, to continuously compile your classes with Gradle, and only that, run this command in a terminal (assuming you use the wrapper):
gradlew -t classes
It will monitor the file system for changes and rerun the classes task on changes. So whenever you make a change to a source file and save it, Gradle will recompile it and the devtools module should pick up the change and reload it.