Migrate to Spring Boot 3 and Kotlin 1.8

build.gradle.kts

@@ -1,19 +1,35 @@
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
 plugins {
-	val kotlinVersion = "1.3.21"
-	id("org.springframework.boot") version "2.1.2.RELEASE"
-	id("org.jetbrains.kotlin.jvm") version kotlinVersion
-	id("org.jetbrains.kotlin.plugin.spring") version kotlinVersion
-	id("org.jetbrains.kotlin.plugin.jpa") version kotlinVersion
-	id("io.spring.dependency-management") version "1.0.6.RELEASE"
+	val kotlinVersion = "1.8.0"
+	id("org.springframework.boot") version "3.0.1"
+	id("io.spring.dependency-management") version "1.1.0"
+	kotlin("jvm") version kotlinVersion
+	kotlin("plugin.spring") version kotlinVersion
+	kotlin("plugin.jpa") version kotlinVersion
 }
 
+group = "hello"
 version = "1.0.0-SNAPSHOT"
+java.sourceCompatibility = JavaVersion.VERSION_17
+
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+	implementation("org.springframework.boot:spring-boot-starter-web")
+	implementation("org.springframework.boot:spring-boot-starter-data-jpa")
+	implementation("org.jetbrains.kotlin:kotlin-reflect")
+	implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
+	implementation("com.h2database:h2")
+
+	testImplementation("org.springframework.boot:spring-boot-starter-test")
+}
 
 tasks.withType<KotlinCompile> {
 	kotlinOptions {
-		jvmTarget = "1.8"
+		jvmTarget = "17"
 		freeCompilerArgs = listOf("-Xjsr305=strict")
 	}
 }
@@ -22,21 +38,3 @@ tasks.withType<Test> {
 	useJUnitPlatform()
 }
 
-repositories {
-	mavenCentral()
-}
-
-dependencies {
-	compile("org.springframework.boot:spring-boot-starter-web")
-	compile("org.springframework.boot:spring-boot-starter-data-jpa")
-	compile("com.h2database:h2")
-	compile("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
-	compile("org.jetbrains.kotlin:kotlin-reflect")
-	compile("com.fasterxml.jackson.module:jackson-module-kotlin")
-	testCompile("org.springframework.boot:spring-boot-starter-test") {
-		exclude(module = "junit")
-	}
-	testImplementation("org.junit.jupiter:junit-jupiter-api")
-	testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine")
-}
-

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.6-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

src/main/kotlin/hello/Application.kt

@@ -44,6 +44,6 @@ class Application {
 
 }
 
-fun main(args: Array<String>) {
-	runApplication<Application>(*args)
+fun main() {
+	runApplication<Application>()
 }

src/main/kotlin/hello/Customer.kt

@@ -1,9 +1,8 @@
 package hello
 
-import javax.persistence.Entity
-import javax.persistence.GeneratedValue
-import javax.persistence.GenerationType
-import javax.persistence.Id
+import jakarta.persistence.Entity
+import jakarta.persistence.GeneratedValue
+import jakarta.persistence.Id
 
 @Entity
 data class Customer(

src/test/kotlin/hello/ApplicationTests.kt

@@ -2,15 +2,12 @@ package hello
 
 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Test
-import org.junit.jupiter.api.extension.ExtendWith
 import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.boot.test.context.SpringBootTest
-import org.springframework.boot.test.context.SpringBootTest.*
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment
 import org.springframework.boot.test.web.client.TestRestTemplate
 import org.springframework.boot.test.web.client.getForObject
-import org.springframework.test.context.junit.jupiter.SpringExtension
 
-@ExtendWith(SpringExtension::class)
 @SpringBootTest(webEnvironment= WebEnvironment.RANDOM_PORT)
 class ApplicationTests(@Autowired private val restTemplate: TestRestTemplate) {