Add LayoutFactory in spring.factories

Instead of a fixed enum of layout types, user can provide custom
layouts via implementations of LayoutFactory in spring.factories.

Author: Dave Syer

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

@@ -20,13 +20,14 @@
 import java.util.Map;
 import java.util.Set;
 
-import groovy.lang.Closure;
 import org.gradle.api.Project;
 import org.gradle.api.plugins.JavaPlugin;
 
 import org.springframework.boot.gradle.buildinfo.BuildInfo;
 import org.springframework.boot.loader.tools.Layout;
-import org.springframework.boot.loader.tools.Layouts;
+import org.springframework.boot.loader.tools.LayoutType;
+
+import groovy.lang.Closure;
 
 /**
  * Gradle DSL Extension for 'Spring Boot'. Most of the time Spring Boot can guess the
@@ -88,7 +89,7 @@ public class SpringBootPluginExtension {
 	 * the MANIFEST.MF 'Main-Class' to be PropertiesLauncher. Gradle will coerce literal
 	 * String values to the correct type.
 	 */
-	LayoutType layout;
+	String layout;
 
 	/**
 	 * Libraries that must be unpacked from fat jars in order to run. Use Strings in the
@@ -145,7 +146,7 @@ public SpringBootPluginExtension(Project project) {
 	 * @return the Layout to use or null if not explicitly set
 	 */
 	public Layout convertLayout() {
-		return (this.layout == null ? null : this.layout.layout);
+		return (this.layout == null ? null : LayoutType.layout(this.layout));
 	}
 
 	public String getMainClass() {
@@ -188,11 +189,11 @@ public void setBackupSource(boolean backupSource) {
 		this.backupSource = backupSource;
 	}
 
-	public LayoutType getLayout() {
+	public String getLayout() {
 		return this.layout;
 	}
 
-	public void setLayout(LayoutType layout) {
+	public void setLayout(String layout) {
 		this.layout = layout;
 	}
 
@@ -276,29 +277,4 @@ public void buildInfo(Closure<?> taskConfigurer) {
 		}
 	}
 
-	/**
-	 * Layout Types.
-	 */
-	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;
-
-		LayoutType(Layout layout) {
-			this.layout = layout;
-		}
-
-	}
-
 }

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

@@ -0,0 +1,31 @@
+/*
+ * 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.loader.tools;
+
+/**
+ * Strategy for creating instances of {@link Layout}.
+ * 
+ * @author Dave Syer
+ *
+ */
+public interface LayoutFactory {
+	
+	Layout getLayout();
+	
+	String getName();
+
+}

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

@@ -0,0 +1,99 @@
+/*
+ * 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.loader.tools;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.springframework.core.io.support.SpringFactoriesLoader;
+
+/**
+ * Archive layout types.
+ */
+public 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 static Map<String, Layout> customTypes;
+
+	private final Layout layout;
+
+	public Layout layout() {
+		return this.layout;
+	}
+
+	LayoutType(Layout layout) {
+		this.layout = layout;
+	}
+
+	public static Layout layout(String value) {
+		try {
+			return valueOf(value).layout();
+		}
+		catch (IllegalArgumentException e) {
+			if (customTypes == null) {
+				customTypes = new HashMap<String, Layout>();
+				lookupCustomTypes();
+			}
+			Layout layout = customTypes.get(value);
+			if (layout == null) {
+				throw new IllegalArgumentException(
+						"Cannot resolve custom layout type: " + value);
+			}
+			return layout;
+		}
+	}
+
+	private static void lookupCustomTypes() {
+		ClassLoader classLoader = LayoutType.class.getClassLoader();
+		List<LayoutFactory> factories = SpringFactoriesLoader
+				.loadFactories(LayoutFactory.class, classLoader);
+		for (LayoutFactory factory : factories) {
+			customTypes.put(factory.getName(), factory.getLayout());
+		}
+	}
+
+}

spring-boot-tools/spring-boot-loader-tools/src/test/java/org/springframework/boot/loader/tools/LayoutTypeTests.java

@@ -0,0 +1,51 @@
+/*
+ * 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.loader.tools;
+
+import org.junit.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Dave Syer
+ *
+ */
+public class LayoutTypeTests {
+
+	@Test
+	public void standardType() {
+		assertThat(LayoutType.layout("DIR")).isEqualTo(LayoutType.valueOf("DIR").layout());
+	}
+
+	@Test
+	public void customType() {
+		assertThat(LayoutType.layout("CUSTOM")).isNotNull();
+	}
+	
+	public static class TestLayoutFactory implements LayoutFactory {
+
+		@Override
+		public Layout getLayout() {
+			return new Layouts.Jar();
+		}
+
+		@Override
+		public String getName() {
+			return "CUSTOM";
+		}}
+
+}

spring-boot-tools/spring-boot-loader-tools/src/test/resources/META-INF/spring.factories

@@ -0,0 +1,2 @@
+org.springframework.boot.loader.tools.LayoutFactory=\
+org.springframework.boot.loader.tools.LayoutTypeTests.TestLayoutFactory

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

@@ -42,8 +42,7 @@
 
 import org.springframework.boot.loader.tools.DefaultLaunchScript;
 import org.springframework.boot.loader.tools.LaunchScript;
-import org.springframework.boot.loader.tools.Layout;
-import org.springframework.boot.loader.tools.Layouts;
+import org.springframework.boot.loader.tools.LayoutType;
 import org.springframework.boot.loader.tools.Libraries;
 import org.springframework.boot.loader.tools.Repackager;
 
@@ -131,7 +130,7 @@ 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.
@@ -228,7 +227,6 @@ private Repackager getRepackager(File source) {
 		repackager.setMainClass(this.mainClass);
 		if (this.layout != null) {
 			getLog().info("Layout: " + this.layout);
-			repackager.setLayout(this.layout.layout());
 		}
 		return repackager;
 	}
@@ -309,53 +307,6 @@ else if (!source.equals(repackaged)) {
 		}
 	}
 
-	/**
-	 * Archive layout types.
-	 */
-	public 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;
-		}
-
-		LayoutType(Layout layout) {
-			this.layout = layout;
-		}
-
-	}
-
 	private static class LoggingRepackager extends Repackager {
 
 		private final Log log;