Map optional dependencies to Maven

Author: rwinch

buildSrc/src/main/java/org/springframework/gradle/maven/MavenPublishingConventionsPlugin.java

@@ -1,8 +1,11 @@
 package org.springframework.gradle.maven;
 
+import io.spring.gradle.propdeps.PropDepsPlugin;
 import org.gradle.api.Action;
 import org.gradle.api.Plugin;
 import org.gradle.api.Project;
+import org.gradle.api.component.AdhocComponentWithVariants;
+import org.gradle.api.plugins.JavaBasePlugin;
 import org.gradle.api.plugins.JavaPlugin;
 import org.gradle.api.plugins.JavaPluginExtension;
 import org.gradle.api.publish.PublishingExtension;
@@ -15,6 +18,8 @@
 import org.gradle.api.publish.maven.MavenPublication;
 import org.gradle.api.publish.maven.plugins.MavenPublishPlugin;
 
+import java.util.function.Consumer;
+
 public class MavenPublishingConventionsPlugin implements Plugin<Project> {
 	@Override
 	public void apply(Project project) {
@@ -27,6 +32,13 @@ public void execute(MavenPublishPlugin mavenPublish) {
 				MavenPublishingConventionsPlugin.this.customizeJavaPlugin(project);
 			}
 		});
+		project.getPlugins().withType(PropDepsPlugin.class).forEach(new Consumer<PropDepsPlugin>() {
+			@Override
+			public void accept(PropDepsPlugin plugin) {
+				AdhocComponentWithVariants component = (AdhocComponentWithVariants) project.getComponents().findByName("java");
+				component.addVariantsFromConfiguration(project.getConfigurations().getByName("optional"), (details) -> details.mapToOptional());
+			}
+		});
 	}
 
 	private void customizePom(MavenPom pom, Project project) {