Convert Gradle plugin from Groovy to Java

Replace existing Groovy code with Java since the Groovy Eclipse tooling
currently forces the use of an old jdt plugin which has formatter bugs.

Fixes gh-4113

Author: philwebb

spring-boot-tools/spring-boot-gradle-plugin/pom.xml

@@ -54,30 +54,6 @@
 			<scope>provided</scope>
 		</dependency>
 	</dependencies>
-	<build>
-		<sourceDirectory>src/main/groovy</sourceDirectory>
-		<plugins>
-			<plugin>
-				<groupId>org.apache.maven.plugins</groupId>
-				<artifactId>maven-compiler-plugin</artifactId>
-				<configuration>
-					<compilerId>groovy-eclipse-compiler</compilerId>
-				</configuration>
-				<dependencies>
-					<dependency>
-						<groupId>org.codehaus.groovy</groupId>
-						<artifactId>groovy-eclipse-compiler</artifactId>
-						<version>2.8.0-01</version>
-					</dependency>
-					<dependency>
-						<groupId>org.codehaus.groovy</groupId>
-						<artifactId>groovy-eclipse-batch</artifactId>
-						<version>2.1.8-01</version>
-					</dependency>
-				</dependencies>
-			</plugin>
-		</plugins>
-	</build>
 	<repositories>
 		<repository>
 			<id>gradle</id>

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

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2012-2015 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.boot.gradle;
+
+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.ApplicationPlugin;
+import org.gradle.api.plugins.BasePlugin;
+import org.gradle.api.plugins.JavaPlugin;
+import org.gradle.api.tasks.compile.JavaCompile;
+import org.springframework.boot.gradle.agent.AgentPluginFeatures;
+import org.springframework.boot.gradle.exclude.ExcludePluginFeatures;
+import org.springframework.boot.gradle.repackage.RepackagePluginFeatures;
+import org.springframework.boot.gradle.resolve.ResolvePluginFeatures;
+import org.springframework.boot.gradle.run.RunPluginFeatures;
+
+/**
+ * Gradle 'Spring Boot' {@link Plugin}.
+ *
+ * @author Phillip Webb
+ * @author Dave Syer
+ */
+class SpringBootPlugin implements Plugin<Project> {
+
+	@Override
+	public void apply(Project project) {
+		project.getPlugins().apply(BasePlugin.class);
+		project.getExtensions().create("springBoot", SpringBootPluginExtension.class);
+		project.getConfigurations().create(VersionManagedDependencies.CONFIGURATION);
+		project.getPlugins().apply(JavaPlugin.class);
+		project.getPlugins().apply(ApplicationPlugin.class);
+		new AgentPluginFeatures().apply(project);
+		new RepackagePluginFeatures().apply(project);
+		new RunPluginFeatures().apply(project);
+		new ResolvePluginFeatures().apply(project);
+		new ExcludePluginFeatures().apply(project);
+		project.getTasks().withType(JavaCompile.class).all(new SetUtf8EncodingAction());
+	}
+
+	private static class SetUtf8EncodingAction implements Action<JavaCompile> {
+
+		@Override
+		public void execute(final JavaCompile compile) {
+			compile.doFirst(new Action<Task>() {
+
+				@Override
+				@SuppressWarnings("deprecation")
+				public void execute(Task t) {
+					if (compile.getOptions().getEncoding() == null) {
+						compile.getOptions().setEncoding("UTF-8");
+					}
+				}
+
+			});
+		}
+
+	}
+
+}