React to the Java plugin being applied rather than always applying it

spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/plugin/SpringBootPlugin.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,7 +20,6 @@ import org.gradle.api.Action;
 import org.gradle.api.Plugin;
 import org.gradle.api.Project;
 import org.gradle.api.Task;
-import org.gradle.api.plugins.JavaPlugin;
 import org.gradle.api.tasks.compile.JavaCompile;
 
 import org.springframework.boot.gradle.SpringBootPluginExtension;
@@ -42,7 +41,6 @@ public class SpringBootPlugin implements Plugin<Project> {
 	public void apply(Project project) {
 		project.getExtensions().create("springBoot", SpringBootPluginExtension.class,
 				project);
-		project.getPlugins().apply(JavaPlugin.class);
 		new AgentPluginFeatures().apply(project);
 		new RepackagePluginFeatures().apply(project);
 		new RunPluginFeatures().apply(project);

spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/repackage/RepackagePluginFeatures.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -53,8 +53,10 @@ public class RepackagePluginFeatures implements PluginFeatures {
 
 	@Override
 	public void apply(Project project) {
+		project.getPlugins().withType(JavaPlugin.class, (javaPlugin) -> {
 			addRepackageTask(project);
 			registerRepackageTaskProperty(project);
+		});
 	}
 
 	private void addRepackageTask(Project project) {

spring-boot-tools/spring-boot-gradle-plugin/src/main/java/org/springframework/boot/gradle/run/RunPluginFeatures.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2016 the original author or authors.
+ * Copyright 2012-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,7 @@ import org.gradle.api.Action;
 import org.gradle.api.Project;
 import org.gradle.api.Task;
 import org.gradle.api.plugins.ExtraPropertiesExtension;
+import org.gradle.api.plugins.JavaPlugin;
 import org.gradle.api.plugins.JavaPluginConvention;
 import org.gradle.api.tasks.SourceSet;
 import org.gradle.api.tasks.application.CreateStartScripts;
@@ -42,8 +43,10 @@ public class RunPluginFeatures implements PluginFeatures {
 
 	@Override
 	public void apply(Project project) {
+		project.getPlugins().withType(JavaPlugin.class, (javaPlugin) -> {
 			mainClassNameFinder(project);
 			addBootRunTask(project);
+		});
 	}
 
 	private void mainClassNameFinder(Project project) {