Upgrade to Kotlin 2.2.0

This commit leverages Kotlin 2.2 which is expected to be the
new baseline for Spring Boot 4.0, so API and language
versions are upgraded to KOTLIN_2_2 as well.

It also enables the -Xannotation-default-target=param-property
compiler flag, mainly for test purpose, in order to avoid the
related warnings and to use what will likely be the default in
an upcoming Kotlin version short term. For more details see
https://youtrack.jetbrains.com/issue/KT-73255.

KotlinPlatformJvmPlugin was a class from an old KMP plugin,
deprecated for a long time and now removed. So its usage in
PluginClasspathGradleBuild has been removed as well.

Signed-off-by: Sébastien Deleuze <[email protected]>

Author: sdeleuze

buildSrc/src/main/java/org/springframework/boot/build/KotlinConventions.java

@@ -54,7 +54,7 @@ class KotlinConventions {
 
 	private static final JvmTarget JVM_TARGET = JvmTarget.JVM_17;
 
-	private static final KotlinVersion KOTLIN_VERSION = KotlinVersion.KOTLIN_2_1;
+	private static final KotlinVersion KOTLIN_VERSION = KotlinVersion.KOTLIN_2_2;
 
 	void apply(Project project) {
 		project.getPlugins().withId("org.jetbrains.kotlin.jvm", (plugin) -> {
@@ -70,7 +70,8 @@ private void configure(KotlinCompile compile) {
 		compilerOptions.getLanguageVersion().set(KOTLIN_VERSION);
 		compilerOptions.getJvmTarget().set(JVM_TARGET);
 		compilerOptions.getAllWarningsAsErrors().set(true);
-		compilerOptions.getFreeCompilerArgs().addAll("-Xsuppress-version-warnings");
+		compilerOptions.getFreeCompilerArgs()
+			.addAll("-Xsuppress-version-warnings", "-Xannotation-default-target=param-property");
 	}
 
 	private void configureDokkatoo(Project project) {

gradle.properties

@@ -14,7 +14,7 @@ hamcrestVersion=3.0
 jacksonVersion=2.19.1
 javaFormatVersion=0.0.47
 junitJupiterVersion=5.13.1
-kotlinVersion=2.1.0
+kotlinVersion=2.2.0
 mavenVersion=3.9.10
 mockitoVersion=5.17.0
 nativeBuildToolsVersion=0.10.6

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/src/test/java/org/springframework/boot/gradle/testkit/PluginClasspathGradleBuild.java

@@ -35,7 +35,6 @@
 import org.gradle.testkit.runner.GradleRunner;
 import org.jetbrains.kotlin.gradle.model.KotlinProject;
 import org.jetbrains.kotlin.gradle.plugin.KotlinCompilerPluginSupportPlugin;
-import org.jetbrains.kotlin.gradle.plugin.KotlinPlatformJvmPlugin;
 import org.jetbrains.kotlin.project.model.LanguageSettings;
 import org.jetbrains.kotlin.tooling.core.KotlinToolingVersion;
 import org.tomlj.Toml;
@@ -85,7 +84,6 @@ private List<File> pluginClasspath() {
 		classpath.add(new File(pathOfJarContaining(DependencyManagementPlugin.class)));
 		if (this.kotlin) {
 			classpath.add(new File(pathOfJarContaining("org.jetbrains.kotlin.cli.common.PropertiesKt")));
-			classpath.add(new File(pathOfJarContaining(KotlinPlatformJvmPlugin.class)));
 			classpath.add(new File(pathOfJarContaining(KotlinProject.class)));
 			classpath.add(new File(pathOfJarContaining(KotlinToolingVersion.class)));
 			classpath.add(new File(pathOfJarContaining("org.jetbrains.kotlin.build.report.metrics.BuildTime")));