diff --git a/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/InterfaceAudience.java b/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/InterfaceAudience.java
index dac0e6f34..934c0896a 100644
--- a/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/InterfaceAudience.java
+++ b/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/InterfaceAudience.java
@@ -46,7 +46,7 @@
 
 @InterfaceAudience.Public
 @InterfaceStability.Evolving
-public class InterfaceAudience {
+public final class InterfaceAudience {
   /**
    * Intended for use by any project or application.
    */
@@ -61,6 +61,10 @@ public class InterfaceAudience {
   @Documented
   @Retention(RetentionPolicy.RUNTIME)
   public @interface LimitedPrivate {
+    /**
+     * The list of projects with access.
+     * @return project names
+     */
     String[] value();
   }
 
@@ -71,5 +75,6 @@ public class InterfaceAudience {
   @Retention(RetentionPolicy.RUNTIME)
   public @interface Private { }
 
-  private InterfaceAudience() { } // Audience can't exist on its own
+  /** Audience can't exist on its own. */
+  private InterfaceAudience() { }
 }
diff --git a/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/InterfaceStability.java b/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/InterfaceStability.java
index af7549ff2..418c245c1 100644
--- a/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/InterfaceStability.java
+++ b/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/InterfaceStability.java
@@ -21,25 +21,29 @@
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 
-import org.apache.yetus.audience.InterfaceAudience.LimitedPrivate;
-import org.apache.yetus.audience.InterfaceAudience.Private;
-import org.apache.yetus.audience.InterfaceAudience.Public;
-
 /**
  * Annotation to inform users of how much to rely on a particular package,
  * class or method not changing over time. Currently the stability can be
  * {@link Stable}, {@link Evolving} or {@link Unstable}. <br>
  *
- * <ul><li>All classes that are annotated with {@link Public} or
- * {@link LimitedPrivate} must have InterfaceStability annotation. </li>
- * <li>Classes that are {@link Private} are to be considered unstable unless
- * a different InterfaceStability annotation states otherwise.</li>
- * <li>Incompatible changes must not be made to classes marked as stable.</li>
+ * <ul><li>All classes that are annotated with
+ * {@link InterfaceAudience.Public} or
+ * {@link InterfaceAudience.LimitedPrivate} must have InterfaceStability
+ * annotation. </li>
+ * <li>Classes that are {@link InterfaceAudience.Private} are to be
+ * considered unstable unless a different InterfaceStability annotation
+ * states otherwise.</li>
+ * <li>Incompatible changes must not be made to classes marked as
+ * stable.</li>
  * </ul>
  */
 @InterfaceAudience.Public
 @InterfaceStability.Evolving
 public class InterfaceStability {
+  /** Default constructor. */
+  public InterfaceStability() {
+  }
+
   /**
    * Can evolve while retaining compatibility for minor release boundaries.
    * can break compatibility only at major release (ie. at m.0).
diff --git a/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/tools/ExcludePrivateAnnotationsStandardDoclet.java b/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/tools/ExcludePrivateAnnotationsStandardDoclet.java
index f64599967..1b25286d8 100644
--- a/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/tools/ExcludePrivateAnnotationsStandardDoclet.java
+++ b/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/tools/ExcludePrivateAnnotationsStandardDoclet.java
@@ -25,7 +25,6 @@
 import java.util.EnumSet;
 import java.util.HashSet;
 import java.util.Set;
-import java.util.TreeSet;
 
 /**
  * A {@link jdk.javadoc.doclet.Doclet}
@@ -33,26 +32,65 @@
  * {@link org.apache.yetus.audience.InterfaceAudience.Private} or
  * {@link org.apache.yetus.audience.InterfaceAudience.LimitedPrivate}.
  * It delegates to the Standard Doclet, and takes the same options.
+ * Subclasses may override {@link #getName()}, {@link #getSupportedOptions()},
+ * and {@link #run(DocletEnvironment)} to customize behavior.
  */
 @InterfaceAudience.Public
 @InterfaceStability.Evolving
 public class ExcludePrivateAnnotationsStandardDoclet extends StandardDoclet {
-  protected DocletEnvironmentProcessor processor = new DocletEnvironmentProcessor();
+  /** Default constructor. */
+  public ExcludePrivateAnnotationsStandardDoclet() {
+    super();
+  }
+
+  /** The doclet environment processor. */
+  // CHECKSTYLE:OFF VisibilityModifier - protected for subclass API compatibility
+  protected DocletEnvironmentProcessor processor =
+      new DocletEnvironmentProcessor();
+  // CHECKSTYLE:ON VisibilityModifier
+
+  /**
+   * Returns the processor used to filter the doclet environment.
+   * @return the doclet environment processor
+   */
+  protected DocletEnvironmentProcessor getProcessor() {
+    return processor;
+  }
 
+  /**
+   * {@inheritDoc}
+   * Returns the name of this doclet.
+   * Subclasses should override to return a distinct name.
+   * @return doclet name
+   */
   @Override
   public String getName() {
     return "ExcludePrivateAnnotationsStandard";
   }
 
+  /**
+   * {@inheritDoc}
+   * Returns the supported options, including stability filter options.
+   * Subclasses may override to add or remove options.
+   * @return set of supported options
+   */
   @Override
   public Set<Option> getSupportedOptions() {
     Set<Option> options = new HashSet<>(super.getSupportedOptions());
-    Set<StabilityOption> stabilityOptions = EnumSet.allOf(StabilityOption.class);
+    Set<StabilityOption> stabilityOptions =
+        EnumSet.allOf(StabilityOption.class);
     stabilityOptions.forEach(o -> o.setProcessor(processor));
     options.addAll(stabilityOptions);
     return options;
   }
 
+  /**
+   * {@inheritDoc}
+   * Runs the doclet, wrapping the environment to filter private elements.
+   * Subclasses may override to apply additional filtering.
+   * @param environment the doclet environment
+   * @return true if successful
+   */
   @Override
   public boolean run(final DocletEnvironment environment) {
     return super.run(processor.wrap(environment));
diff --git a/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/tools/IncludePublicAnnotationsStandardDoclet.java b/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/tools/IncludePublicAnnotationsStandardDoclet.java
index 3b308d1a0..601962e24 100644
--- a/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/tools/IncludePublicAnnotationsStandardDoclet.java
+++ b/audience-annotations-component/audience-annotations/src/main/java/org/apache/yetus/audience/tools/IncludePublicAnnotationsStandardDoclet.java
@@ -38,12 +38,30 @@
 @InterfaceStability.Evolving
 public class IncludePublicAnnotationsStandardDoclet
         extends ExcludePrivateAnnotationsStandardDoclet {
+  /** Default constructor. */
+  public IncludePublicAnnotationsStandardDoclet() {
+    super();
+  }
+
+  /**
+   * {@inheritDoc}
+   * Initializes the doclet, marking unannotated classes as private.
+   * Subclasses may override to apply additional initialization.
+   * @param locale the locale for messages
+   * @param reporter the reporter for messages
+   */
   @Override
   public void init(final Locale locale, final Reporter reporter) {
-    processor.treatUnannotatedClassesAsPrivate();
+    getProcessor().treatUnannotatedClassesAsPrivate();
     super.init(locale, reporter);
   }
 
+  /**
+   * {@inheritDoc}
+   * Returns the name of this doclet.
+   * Subclasses should override to return a distinct name.
+   * @return doclet name
+   */
   @Override
   public String getName() {
     return "IncludePublicAnnotationsStandard";
diff --git a/pom.xml b/pom.xml
index 4da84c6ad..47f653629 100644
--- a/pom.xml
+++ b/pom.xml
@@ -145,11 +145,19 @@
           <version>${maven-javadoc-plugin.version}</version>
           <configuration>
             <notimestamp>true</notimestamp><!-- avoid noise for svn/gitpubsub -->
+            <release combine.self="override"></release>
             <additionalOptions>${jigsaw.avoidance}</additionalOptions>
             <additionalJOption>-J${jigsaw.avoidance}</additionalJOption>
           </configuration>
         </plugin>
 
+        <plugin>
+          <artifactId>maven-antrun-plugin</artifactId>
+          <configuration>
+            <exportAntProperties>false</exportAntProperties>
+          </configuration>
+        </plugin>
+
         <plugin>
           <artifactId>maven-clean-plugin</artifactId>
           <configuration>
@@ -308,7 +316,6 @@
               <additionalOptions>
                 <additionalOption>${jigsaw.avoidance}</additionalOption>
               </additionalOptions>
-
               <additionalJOption>-J${jigsaw.avoidance}</additionalJOption>
 
               <doclet>org.apache.yetus.audience.tools.ExcludePrivateAnnotationsStandardDoclet</doclet>
diff --git a/yetus-maven-plugin/src/main/java/org/apache/yetus/maven/plugin/fileops/CreateDirsMojo.java b/yetus-maven-plugin/src/main/java/org/apache/yetus/maven/plugin/fileops/CreateDirsMojo.java
index bec4af8d5..0dc5caed2 100644
--- a/yetus-maven-plugin/src/main/java/org/apache/yetus/maven/plugin/fileops/CreateDirsMojo.java
+++ b/yetus-maven-plugin/src/main/java/org/apache/yetus/maven/plugin/fileops/CreateDirsMojo.java
@@ -34,6 +34,11 @@
 @InterfaceStability.Unstable
 public final class CreateDirsMojo extends AbstractMojo {
 
+  /** Default constructor. */
+  public CreateDirsMojo() {
+    super();
+  }
+
   /**
    * Location of the dirName.
    */
diff --git a/yetus-maven-plugin/src/main/java/org/apache/yetus/maven/plugin/fileops/CreateSymLinkMojo.java b/yetus-maven-plugin/src/main/java/org/apache/yetus/maven/plugin/fileops/CreateSymLinkMojo.java
index d0e614674..2026ae4a9 100644
--- a/yetus-maven-plugin/src/main/java/org/apache/yetus/maven/plugin/fileops/CreateSymLinkMojo.java
+++ b/yetus-maven-plugin/src/main/java/org/apache/yetus/maven/plugin/fileops/CreateSymLinkMojo.java
@@ -39,6 +39,11 @@
 @InterfaceStability.Unstable
 public final class CreateSymLinkMojo extends AbstractMojo {
 
+  /** Default constructor. */
+  public CreateSymLinkMojo() {
+    super();
+  }
+
   /**
    * Location of the target.
    */
diff --git a/yetus-maven-plugin/src/main/java/org/apache/yetus/maven/plugin/fileops/MakeBins4Libs.java b/yetus-maven-plugin/src/main/java/org/apache/yetus/maven/plugin/fileops/MakeBins4Libs.java
index d76989792..a91b21c48 100644
--- a/yetus-maven-plugin/src/main/java/org/apache/yetus/maven/plugin/fileops/MakeBins4Libs.java
+++ b/yetus-maven-plugin/src/main/java/org/apache/yetus/maven/plugin/fileops/MakeBins4Libs.java
@@ -45,6 +45,11 @@
 @InterfaceStability.Unstable
 public final class MakeBins4Libs extends AbstractMojo {
 
+  /** Default constructor. */
+  public MakeBins4Libs() {
+    super();
+  }
+
   /**
    * bin dir.
    */