Repackager: layouts refactoring. Layouts are now pluggable: specify fully qualified name of the class implementing the Layout interface, or use known legacy aliases (JAR, ZIP, DIR, ...)

Author: patrikbeno

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

@@ -38,27 +38,6 @@ import org.springframework.boot.loader.tools.Layouts
  */
 public class SpringBootPluginExtension {
 
-	static enum LayoutType {
-
-		JAR(new Layouts.Jar()),
-
-		WAR(new Layouts.War()),
-
-		ZIP(new Layouts.Expanded()),
-
-		DIR(new Layouts.Expanded()),
-
-		MODULE(new Layouts.Module()),
-
-		NONE(new Layouts.None());
-
-		Layout layout;
-
-		private LayoutType(Layout layout) {
-			this.layout = layout;
-		}
-	}
-
 	/**
 	 * 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
@@ -99,14 +78,14 @@ public class SpringBootPluginExtension {
 	 * PropertiesLauncher. Gradle will coerce literal String values to the
 	 * correct type.
 	 */
-	LayoutType layout;
+	String layout;
 
 	/**
 	 * Convenience method for use in a custom task.
 	 * @return the Layout to use or null if not explicitly set
 	 */
 	Layout convertLayout() {
-		(layout == null ? null : layout.layout)
+        Layouts.resolve(layout)
 	}
 
 	/**

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

@@ -28,6 +28,7 @@
 import org.gradle.api.tasks.TaskAction;
 import org.gradle.api.tasks.bundling.Jar;
 import org.springframework.boot.gradle.SpringBootPluginExtension;
+import org.springframework.boot.loader.tools.Layout;
 import org.springframework.boot.loader.tools.Repackager;
 import org.springframework.util.FileCopyUtils;
 
@@ -165,9 +166,7 @@ private void repackage(File file) {
 			}
 			Repackager repackager = new LoggingRepackager(file);
 			setMainClass(repackager);
-			if (this.extension.convertLayout() != null) {
-				repackager.setLayout(this.extension.convertLayout());
-			}
+			repackager.setLayout(this.extension.convertLayout());
 			repackager.setBackupSource(this.extension.isBackupSource());
 			try {
 				repackager.repackage(file, this.libraries);

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

@@ -33,6 +33,36 @@
  */
 public class Layouts {
 
+	static private Class<? extends Layout> defaultLayout = Layouts.Jar.class;
+
+	static private Map<String, Class<?>> map = new HashMap<String, Class<?>>() {{
+		for (Class<?> cls : Layouts.class.getClasses()) {
+			if (Layout.class.isAssignableFrom(cls)) {
+				put(toSimpleLayoutName(cls), (Class) cls);
+			}
+		}
+	}};
+
+	static public Layout resolve(String name) throws RuntimeException {
+		try {
+			Class<?> cls = null;
+			if (cls == null) { cls = map.get(name); };
+			if (cls == null) { cls = Class.forName(name); }
+			if (cls == null) { cls = defaultLayout; }
+			return (Layout) cls.newInstance();
+		}
+		catch (Exception e) {
+			throw new RuntimeException(String.format(
+					"Cannot resolve layout `%s`. Provide a fully qualified class name or of the following: %s",
+					name, map.keySet()
+			), e);
+		}
+	}
+
+	static private String toSimpleLayoutName(Class<?> cls) {
+		return cls.getSimpleName().toUpperCase();
+	}
+
 	/**
 	 * Return the a layout for the given source file.
 	 * @param file the source file
@@ -90,9 +120,12 @@ public static class Expanded extends Jar {
 		public String getLauncherClassName() {
 			return "org.springframework.boot.loader.PropertiesLauncher";
 		}
-
 	}
 
+	public static class Zip extends Expanded {}
+
+	public static class Dir extends Expanded {}
+
 	/**
 	 * No layout.
 	 */

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

@@ -0,0 +1,29 @@
+package org.springframework.boot.loader.tools.layout;
+
+import org.springframework.boot.loader.tools.Layout;
+import org.springframework.boot.loader.tools.LibraryScope;
+
+/**
+ * @author <a href="mailto:patrikbeno@gmail.com">Patrik Beno</a>
+ */
+public class BaseLayout implements Layout {
+	@Override
+	public String getLauncherClassName() {
+		return null;
+	}
+
+	@Override
+	public String getLibraryDestination(String libraryName, LibraryScope scope) {
+		return null;
+	}
+
+	@Override
+	public String getClassesLocation() {
+		return "";
+	}
+
+	@Override
+	public boolean isExecutable() {
+		return false;
+	}
+}

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

@@ -34,7 +34,6 @@
 import org.apache.maven.plugins.annotations.ResolutionScope;
 import org.apache.maven.project.MavenProject;
 import org.apache.maven.project.MavenProjectHelper;
-import org.springframework.boot.loader.tools.Layout;
 import org.springframework.boot.loader.tools.Layouts;
 import org.springframework.boot.loader.tools.Libraries;
 import org.springframework.boot.loader.tools.Repackager;
@@ -115,7 +114,7 @@ public class RepackageMojo extends AbstractDependencyFilterMojo {
 	 * @since 1.0
 	 */
 	@Parameter
-	private LayoutType layout;
+	private String layout;
 
 	/**
 	 * A list of the libraries that must be unpacked from fat jars in order to run.
@@ -156,10 +155,9 @@ protected String findMainMethod(JarFile source) throws IOException {
 			}
 		};
 		repackager.setMainClass(this.mainClass);
-		if (this.layout != null) {
-			getLog().info("Layout: " + this.layout);
-			repackager.setLayout(this.layout.layout());
-		}
+
+		getLog().info("Layout: " + this.layout);
+		repackager.setLayout(Layouts.resolve(this.layout));
 
 		Set<Artifact> artifacts = filterDependencies(this.project.getArtifacts(),
 				getFilters());
@@ -190,47 +188,4 @@ private File getTargetFile() {
 				+ this.project.getPackaging());
 	}
 
-	public static enum LayoutType {
-
-		/**
-		 * Jar Layout
-		 */
-		JAR(new Layouts.Jar()),
-
-		/**
-		 * War Layout
-		 */
-		WAR(new Layouts.War()),
-
-		/**
-		 * Zip Layout
-		 */
-		ZIP(new Layouts.Expanded()),
-
-		/**
-		 * Dir Layout
-		 */
-		DIR(new Layouts.Expanded()),
-
-		/**
-		 * Module Layout
-		 */
-		MODULE(new Layouts.Module()),
-
-		/**
-		 * No Layout
-		 */
-		NONE(new Layouts.None());
-
-		private final Layout layout;
-
-		public Layout layout() {
-			return this.layout;
-		}
-
-		private LayoutType(Layout layout) {
-			this.layout = layout;
-		}
-	}
-
 }