Kotlin plugin conditionally deactivated on JDK 9

build.gradle

@@ -326,8 +326,10 @@ project("spring-build-src") {
 project("spring-core") {
 	description = "Spring Core"
 
-	// Disabled since Kotlin compiler does not support JDK 9 yet
-	//apply plugin: "kotlin"
+	// Kotlin compiler does not support JDK 9 yet
+	if (!JavaVersion.current().java9Compatible) {
+		apply plugin: "kotlin"
+	}
 
 	// As of Spring 4.0.3, spring-core includes asm 5.x and repackages cglib 3.2, inlining
 	// both into the spring-core jar. cglib 3.2 itself depends on asm 5.x and is therefore
@@ -428,8 +430,10 @@ project("spring-core") {
 project("spring-beans") {
 	description = "Spring Beans"
 
-	// Disabled since Kotlin compiler does not support JDK 9 yet
-	//apply plugin: "kotlin"
+	// Kotlin compiler does not support JDK 9 yet
+	if (!JavaVersion.current().java9Compatible) {
+		apply plugin: "kotlin"
+	}
 
 	dependencies {
 		compile(project(":spring-core"))
@@ -455,7 +459,7 @@ project("spring-beans-groovy") {
 	}
 
 	// this module's Java and Groovy sources need to be compiled together
-	compileJava.enabled=false
+	compileJava.enabled = false
 	sourceSets {
 		main {
 			groovy {
@@ -577,8 +581,10 @@ project("spring-oxm") {
 project("spring-messaging") {
 	description = "Spring Messaging"
 
-	// Disabled since Kotlin compiler does not support JDK 9 yet
-	//apply plugin: "kotlin"
+	// Kotlin compiler does not support JDK 9 yet
+	if (!JavaVersion.current().java9Compatible) {
+		apply plugin: "kotlin"
+	}
 
 	dependencies {
 		compile(project(":spring-beans"))
@@ -720,9 +726,11 @@ project("spring-context-indexer") {
 project("spring-web") {
 	description = "Spring Web"
 
+	// Kotlin compiler does not support JDK 9 yet
+	if (!JavaVersion.current().java9Compatible) {
+		apply plugin: "kotlin"
+	}
 	apply plugin: "groovy"
-	// Disabled since Kotlin compiler does not support JDK 9 yet
-	//apply plugin: "kotlin"
 
 	dependencies {
 		compile(project(":spring-aop"))  // for JaxWsPortProxyFactoryBean
@@ -811,8 +819,10 @@ project("spring-web") {
 project("spring-web-reactive") {
 	description = "Spring Web Reactive"
 
-	// Disabled since Kotlin compiler does not support JDK 9 yet
-	//apply plugin: "kotlin"
+	// Kotlin compiler does not support JDK 9 yet
+	if (!JavaVersion.current().java9Compatible) {
+		apply plugin: "kotlin"
+	}
 
 	dependencies {
 		compile(project(":spring-core"))