plugins: support for overriding layout-provided launcher class

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

@@ -59,6 +59,11 @@ public class SpringBootPluginExtension {
 		}
 	}
 
+    /**
+     * Launcher class, replaces the default specified by layout. Optional.
+     */
+    String launcherClass;
+
 	/**
 	 * The main class that should be run. Instead of setting this explicitly you can use the
 	 * 'mainClassName' of the project or the 'main' of the 'run' task. If not specified the

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

@@ -165,6 +165,7 @@ private void repackage(File file) {
 			}
 			Repackager repackager = new LoggingRepackager(file);
 			setMainClass(repackager);
+			setLauncherClass(repackager);
 			if (this.extension.convertLayout() != null) {
 				repackager.setLayout(this.extension.convertLayout());
 			}
@@ -201,6 +202,12 @@ else if (getProject().getTasks().getByName("run").hasProperty("main")) {
 			getLogger().info("Setting mainClass: " + mainClass);
 			repackager.setMainClass(mainClass);
 		}
+
+		private void setLauncherClass(Repackager repackager) {
+			String launcherClass = extension.getLauncherClass();
+			getLogger().info("Setting mainClass: " + launcherClass);
+			repackager.setLauncherClass(launcherClass);
+		}
 	}
 
 	/**

spring-boot-tools/spring-boot-loader-tools/src/main/java/org/springframework/boot/loader/tools/Repackager.java

@@ -42,6 +42,8 @@ public class Repackager {
 
 	private static final byte[] ZIP_FILE_HEADER = new byte[] { 'P', 'K', 3, 4 };
 
+	private String launcherClass;
+
 	private String mainClass;
 
 	private boolean backupSource = true;
@@ -58,6 +60,10 @@ public Repackager(File source) {
 		this.layout = Layouts.forFile(source);
 	}
 
+	public void setLauncherClass(String launcherClass) {
+		this.launcherClass = launcherClass;
+	}
+
 	/**
 	 * Sets the main class that should be run. If not specified the value from the
 	 * MANIFEST will be used, or if no manifest entry is found the archive will be
@@ -229,7 +235,9 @@ private Manifest buildManifest(JarFile source) throws IOException {
 		if (startClass == null) {
 			startClass = findMainMethod(source);
 		}
-		String launcherClassName = this.layout.getLauncherClassName();
+		String launcherClassName = (launcherClass != null)
+				? launcherClass
+				: layout.getLauncherClassName();
 		if (launcherClassName != null) {
 			manifest.getMainAttributes()
 					.putValue(MAIN_CLASS_ATTRIBUTE, launcherClassName);

spring-boot-tools/spring-boot-maven-plugin/src/main/java/org/springframework/boot/maven/RepackageMojo.java

@@ -100,6 +100,12 @@ public class RepackageMojo extends AbstractDependencyFilterMojo {
 	@Parameter
 	private String classifier;
 
+	/**
+	 * Name of the launcher class; overrides the one specified by layout.
+	 */
+	@Parameter
+	private String launcherClass;
+
 	/**
 	 * The name of the main class. If not specified the first compiled class found that
 	 * contains a 'main' method will be used.
@@ -156,6 +162,7 @@ protected String findMainMethod(JarFile source) throws IOException {
 			}
 		};
 		repackager.setMainClass(this.mainClass);
+		repackager.setLauncherClass(this.launcherClass);
 		if (this.layout != null) {
 			getLog().info("Layout: " + this.layout);
 			repackager.setLayout(this.layout.layout());