Polish 'Add JVM options to prevent warnings with asciidoctor'

See gh-32123

buildSrc/src/main/java/org/springframework/boot/build/AsciidoctorConventions.java

@@ -26,6 +26,7 @@ import org.asciidoctor.gradle.jvm.AbstractAsciidoctorTask;
 import org.asciidoctor.gradle.jvm.AsciidoctorJExtension;
 import org.asciidoctor.gradle.jvm.AsciidoctorJPlugin;
 import org.asciidoctor.gradle.jvm.AsciidoctorTask;
+import org.gradle.api.JavaVersion;
 import org.gradle.api.Project;
 import org.gradle.api.tasks.PathSensitivity;
 import org.gradle.api.tasks.Sync;
@@ -118,6 +119,7 @@ class AsciidoctorConventions {
 		asciidoctorTask.configurations(EXTENSIONS_CONFIGURATION_NAME);
 		configureCommonAttributes(project, asciidoctorTask);
 		configureOptions(asciidoctorTask);
+		configureForkOptions(asciidoctorTask);
 		asciidoctorTask.baseDirFollowsSourceDir();
 		createSyncDocumentationSourceTask(project, asciidoctorTask);
 		if (asciidoctorTask instanceof AsciidoctorTask) {
@@ -136,6 +138,14 @@ class AsciidoctorConventions {
 		asciidoctorTask.attributes(attributes);
 	}
 
+	// See https://github.com/asciidoctor/asciidoctor-gradle-plugin/issues/597
+	private void configureForkOptions(AbstractAsciidoctorTask asciidoctorTask) {
+		if (JavaVersion.current().isCompatibleWith(JavaVersion.VERSION_16)) {
+			asciidoctorTask.forkOptions((options) -> options.jvmArgs("--add-opens", "java.base/sun.nio.ch=ALL-UNNAMED",
+					"--add-opens", "java.base/java.io=ALL-UNNAMED"));
+		}
+	}
+
 	private String determineGitHubTag(Project project) {
 		String version = "v" + project.getVersion();
 		return (version.endsWith("-SNAPSHOT")) ? "2.6.x" : version;

spring-boot-project/spring-boot-actuator-autoconfigure/build.gradle

@@ -222,18 +222,12 @@ asciidoctor {
 	sources {
 		include "index.adoc"
 	}
-	forkOptions {
-		jvmArgs "--add-opens", "java.base/sun.nio.ch=ALL-UNNAMED", "--add-opens", "java.base/java.io=ALL-UNNAMED"
-	}
 }
 
 task asciidoctorPdf(type: org.asciidoctor.gradle.jvm.AsciidoctorTask) {
 	sources {
 		include "index.adoc"
 	}
-	forkOptions {
-		jvmArgs "--add-opens", "java.base/sun.nio.ch=ALL-UNNAMED", "--add-opens", "java.base/java.io=ALL-UNNAMED"
-	}
 }
 
 task zip(type: Zip) {

spring-boot-project/spring-boot-docs/build.gradle

@@ -332,27 +332,18 @@ asciidoctor {
 	sources {
 		include "*.singleadoc"
 	}
-	forkOptions {
-		jvmArgs "--add-opens", "java.base/sun.nio.ch=ALL-UNNAMED", "--add-opens", "java.base/java.io=ALL-UNNAMED"
-	}
 }
 
 task asciidoctorPdf(type: org.asciidoctor.gradle.jvm.AsciidoctorTask) {
 	sources {
 		include "*.singleadoc"
 	}
-	forkOptions {
-		jvmArgs "--add-opens", "java.base/sun.nio.ch=ALL-UNNAMED", "--add-opens", "java.base/java.io=ALL-UNNAMED"
-	}
 }
 
 task asciidoctorMultipage(type: org.asciidoctor.gradle.jvm.AsciidoctorTask) {
 	sources {
 		include "*.adoc"
 	}
-	forkOptions {
-		jvmArgs "--add-opens", "java.base/sun.nio.ch=ALL-UNNAMED", "--add-opens", "java.base/java.io=ALL-UNNAMED"
-	}
 }
 
 syncDocumentationSourceForAsciidoctor {

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/build.gradle

@@ -79,18 +79,12 @@ asciidoctor {
 	sources {
 		include "index.adoc"
 	}
-	forkOptions {
-		jvmArgs "--add-opens", "java.base/sun.nio.ch=ALL-UNNAMED", "--add-opens", "java.base/java.io=ALL-UNNAMED"
-	}
 }
 
 task asciidoctorPdf(type: org.asciidoctor.gradle.jvm.AsciidoctorTask) {
 	sources {
 		include "index.adoc"
 	}
-	forkOptions {
-		jvmArgs "--add-opens", "java.base/sun.nio.ch=ALL-UNNAMED", "--add-opens", "java.base/java.io=ALL-UNNAMED"
-	}
 }
 
 javadoc {

spring-boot-project/spring-boot-tools/spring-boot-maven-plugin/build.gradle

@@ -94,18 +94,12 @@ asciidoctor {
 	sources {
 		include "index.adoc"
 	}
-	forkOptions {
-		jvmArgs "--add-opens", "java.base/sun.nio.ch=ALL-UNNAMED", "--add-opens", "java.base/java.io=ALL-UNNAMED"
-	}
 }
 
 task asciidoctorPdf(type: org.asciidoctor.gradle.jvm.AsciidoctorTask) {
 	sources {
 		include "index.adoc"
 	}
-	forkOptions {
-		jvmArgs "--add-opens", "java.base/sun.nio.ch=ALL-UNNAMED", "--add-opens", "java.base/java.io=ALL-UNNAMED"
-	}
 }
 
 syncDocumentationSourceForAsciidoctorPdf {