Remove layout parameters from build-image Maven goal

This commit removes the `layout` and `layoutFactory` parameters
from the `build-image` goal in the Maven plugin while retaining
them for the `repackage` goal. The `build-image` goal currently
only supports jar archives, so allowing other layout types to be
configured for the goal could cause confusion.

Fixes gh-24105

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

 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -53,6 +53,7 @@ import org.springframework.boot.loader.tools.layer.CustomLayers;
  * Abstract base class for classes that work with an {@link Packager}.
  *
  * @author Phillip Webb
+ * @author Scott Frederick
  * @since 2.3.0
  */
 public abstract class AbstractPackagerMojo extends AbstractDependencyFilterMojo {
@@ -81,24 +82,6 @@ public abstract class AbstractPackagerMojo extends AbstractDependencyFilterMojo
 	@Parameter
 	private String mainClass;
 
-	/**
-	 * The type of archive (which corresponds to how the dependencies are laid out inside
-	 * it). Possible values are {@code JAR}, {@code WAR}, {@code ZIP}, {@code DIR},
-	 * {@code NONE}. Defaults to a guess based on the archive type.
-	 * @since 1.0.0
-	 */
-	@Parameter(property = "spring-boot.repackage.layout")
-	private LayoutType layout;
-
-	/**
-	 * The layout factory that will be used to create the executable archive if no
-	 * explicit layout is set. Alternative layouts implementations can be provided by 3rd
-	 * parties.
-	 * @since 1.5.0
-	 */
-	@Parameter
-	private LayoutFactory layoutFactory;
-
 	/**
 	 * Exclude Spring Boot devtools from the repackaged archive.
 	 * @since 1.3.0
@@ -121,6 +104,24 @@ public abstract class AbstractPackagerMojo extends AbstractDependencyFilterMojo
 	@Parameter
 	private Layers layers;
 
+	/**
+	 * Return the type of archive that should be packaged by this MOJO.
+	 * @return {@code null}, indicating a layout type will be chosen based on the original
+	 * archive type
+	 */
+	protected LayoutType getLayout() {
+		return null;
+	}
+
+	/**
+	 * Return the layout factory that will be used to determine the {@link LayoutType} if
+	 * no explicit layout is set.
+	 * @return {@code null}, indicating a default layout factory will be chosen
+	 */
+	protected LayoutFactory getLayoutFactory() {
+		return null;
+	}
+
 	/**
 	 * Return a {@link Packager} configured for this MOJO.
 	 * @param <P> the packager type
@@ -129,12 +130,13 @@ public abstract class AbstractPackagerMojo extends AbstractDependencyFilterMojo
 	 */
 	protected <P extends Packager> P getConfiguredPackager(Supplier<P> supplier) {
 		P packager = supplier.get();
-		packager.setLayoutFactory(this.layoutFactory);
+		packager.setLayoutFactory(getLayoutFactory());
 		packager.addMainClassTimeoutWarningListener(new LoggingMainClassTimeoutWarningListener(this::getLog));
 		packager.setMainClass(this.mainClass);
-		if (this.layout != null) {
-			getLog().info("Layout: " + this.layout);
-			packager.setLayout(this.layout.layout());
+		LayoutType layout = getLayout();
+		if (layout != null) {
+			getLog().info("Layout: " + layout);
+			packager.setLayout(layout.layout());
 		}
 		if (this.layers != null && this.layers.isEnabled()) {
 			packager.setLayers((this.layers.getConfiguration() != null)

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

 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 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.
@@ -36,6 +36,7 @@ import org.apache.maven.plugins.annotations.ResolutionScope;
 
 import org.springframework.boot.loader.tools.DefaultLaunchScript;
 import org.springframework.boot.loader.tools.LaunchScript;
+import org.springframework.boot.loader.tools.LayoutFactory;
 import org.springframework.boot.loader.tools.Libraries;
 import org.springframework.boot.loader.tools.Repackager;
 
@@ -48,6 +49,7 @@ import org.springframework.boot.loader.tools.Repackager;
  * @author Dave Syer
  * @author Stephane Nicoll
  * @author Björn Lindström
+ * @author Scott Frederick
  * @since 1.0.0
  */
 @Mojo(name = "repackage", defaultPhase = LifecyclePhase.PACKAGE, requiresProject = true, threadSafe = true,
@@ -152,6 +154,45 @@ public class RepackageMojo extends AbstractPackagerMojo {
 	@Parameter(defaultValue = "${project.build.outputTimestamp}")
 	private String outputTimestamp;
 
+	/**
+	 * The type of archive (which corresponds to how the dependencies are laid out inside
+	 * it). Possible values are {@code JAR}, {@code WAR}, {@code ZIP}, {@code DIR},
+	 * {@code NONE}. Defaults to a guess based on the archive type.
+	 * @since 1.0.0
+	 */
+	@Parameter(property = "spring-boot.repackage.layout")
+	private LayoutType layout;
+
+	/**
+	 * The layout factory that will be used to create the executable archive if no
+	 * explicit layout is set. Alternative layouts implementations can be provided by 3rd
+	 * parties.
+	 * @since 1.5.0
+	 */
+	@Parameter
+	private LayoutFactory layoutFactory;
+
+	/**
+	 * Return the type of archive that should be packaged by this MOJO.
+	 * @return the value of the {@code layout} parameter, or {@code null} if the parameter
+	 * is not provided
+	 */
+	@Override
+	protected LayoutType getLayout() {
+		return this.layout;
+	}
+
+	/**
+	 * Return the layout factory that will be used to determine the {@link LayoutType} if
+	 * no explicit layout is set.
+	 * @return the value of the {@code layoutFactory} parameter, or {@code null} if the
+	 * parameter is not provided
+	 */
+	@Override
+	protected LayoutFactory getLayoutFactory() {
+		return this.layoutFactory;
+	}
+
 	@Override
 	public void execute() throws MojoExecutionException, MojoFailureException {
 		if (this.project.getPackaging().equals("pom")) {