--- old/src/java.naming/share/classes/javax/naming/CompositeName.java	2020-08-25 15:53:55.574355171 +0100
+++ new/src/java.naming/share/classes/javax/naming/CompositeName.java	2020-08-25 15:53:55.418358014 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -562,12 +562,16 @@
     }
 
     /**
-     * Overridden to avoid implementation dependency.
      * @serialData The number of components (an {@code int}) followed by
      * the individual components (each a {@code String}).
+     *
+     * @param s the {@code ObjectOutputStream} to write to
+     * @throws java.io.IOException if an I/O error occurs.
      */
+    @java.io.Serial
     private void writeObject(java.io.ObjectOutputStream s)
             throws java.io.IOException {
+        // Overridden to avoid implementation dependency
         s.writeInt(size());
         Enumeration<String> comps = getAll();
         while (comps.hasMoreElements()) {
@@ -576,10 +580,19 @@
     }
 
     /**
-     * Overridden to avoid implementation dependency.
+     * Initializes the {@code CompositeName} from deserialized data.
+     *
+     * See {@code writeObject} for a description of the serial form.
+     *
+     * @param s the {@code ObjectInputStream} to read from
+     * @throws java.io.IOException if an I/O error occurs.
+     * @throws ClassNotFoundException if the class of a serialized object
+     *         could not be found.
      */
+    @java.io.Serial
     private void readObject(java.io.ObjectInputStream s)
             throws java.io.IOException, ClassNotFoundException {
+        // Overridden to avoid implementation dependency
         impl = new NameImpl(null);  // null means use default syntax
         int n = s.readInt();    // number of components
         try {
--- old/src/java.naming/share/classes/javax/naming/CompoundName.java	2020-08-25 15:53:56.142344817 +0100
+++ new/src/java.naming/share/classes/javax/naming/CompoundName.java	2020-08-25 15:53:55.982347733 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -547,13 +547,17 @@
     }
 
     /**
-     * Overridden to avoid implementation dependency.
      * @serialData The syntax {@code Properties}, followed by
      * the number of components (an {@code int}), and the individual
      * components (each a {@code String}).
+     *
+     * @param s the {@code ObjectOutputStream} to write to
+     * @throws java.io.IOException if an I/O error occurs.
      */
+    @java.io.Serial
     private void writeObject(java.io.ObjectOutputStream s)
             throws java.io.IOException {
+        // Overridden to avoid implementation dependency
         s.writeObject(mySyntax);
         s.writeInt(size());
         Enumeration<String> comps = getAll();
@@ -563,10 +567,19 @@
     }
 
     /**
-     * Overridden to avoid implementation dependency.
+     * Initializes the {@code CompoundName} from deserialized data.
+     *
+     * See {@code writeObject} for a description of the serial form.
+     *
+     * @param s the {@code ObjectInputStream} to read from
+     * @throws java.io.IOException if an I/O error occurs.
+     * @throws ClassNotFoundException if the class of a serialized object
+     *         could not be found.
      */
+    @java.io.Serial
     private void readObject(java.io.ObjectInputStream s)
             throws java.io.IOException, ClassNotFoundException {
+        // Overridden to avoid implementation dependency.
         mySyntax = (Properties)s.readObject();
         impl = new NameImpl(mySyntax);
         int n = s.readInt();    // number of components
--- old/src/java.naming/share/classes/javax/naming/directory/BasicAttribute.java	2020-08-25 15:53:56.726334173 +0100
+++ new/src/java.naming/share/classes/javax/naming/directory/BasicAttribute.java	2020-08-25 15:53:56.566337089 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -494,13 +494,17 @@
 //  ---- serialization methods
 
     /**
-     * Overridden to avoid exposing implementation details
-     * @serialData Default field (the attribute ID -- a String),
-     * followed by the number of values (an int), and the
+     * @serialData Default field (the attribute ID - a {@code String}),
+     * followed by the number of values (an {@code int}), and the
      * individual values.
+     *
+     * @param s the {@code ObjectOutputStream} to write to
+     * @throws java.io.IOException if an I/O error occurs.
      */
+    @java.io.Serial
     private void writeObject(java.io.ObjectOutputStream s)
             throws java.io.IOException {
+        // Overridden to avoid exposing implementation details
         s.defaultWriteObject(); // write out the attrID
         s.writeInt(values.size());
         for (int i = 0; i < values.size(); i++) {
@@ -509,10 +513,19 @@
     }
 
     /**
-     * Overridden to avoid exposing implementation details.
+     * Initializes the {@code BasicAttribute} from deserialized data.
+     *
+     * See {@code writeObject} for a description of the serial form.
+     *
+     * @param s the {@code ObjectInputStream} to read from
+     * @throws java.io.IOException if an I/O error occurs.
+     * @throws ClassNotFoundException if the class of a serialized object
+     *         could not be found.
      */
+    @java.io.Serial
     private void readObject(java.io.ObjectInputStream s)
             throws java.io.IOException, ClassNotFoundException {
+        // Overridden to avoid exposing implementation details.
         s.defaultReadObject();  // read in the attrID
         int n = s.readInt();    // number of values
         values = new Vector<>(Math.min(1024, n));
--- old/src/java.naming/share/classes/javax/naming/directory/BasicAttributes.java	2020-08-25 15:53:57.298323747 +0100
+++ new/src/java.naming/share/classes/javax/naming/directory/BasicAttributes.java	2020-08-25 15:53:57.142326590 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -279,13 +279,17 @@
     }
 
     /**
-     * Overridden to avoid exposing implementation details.
-     * @serialData Default field (ignoreCase flag -- a boolean), followed by
+     * @serialData Default field (ignoreCase flag - a {@code boolean}), followed by
      * the number of attributes in the set
-     * (an int), and then the individual Attribute objects.
+     * (an {@code int}), and then the individual {@code Attribute} objects.
+     *
+     * @param s the {@code ObjectOutputStream} to write to
+     * @throws java.io.IOException if an I/O error occurs.
      */
+    @java.io.Serial
     private void writeObject(java.io.ObjectOutputStream s)
             throws java.io.IOException {
+        // Overridden to avoid exposing implementation details
         s.defaultWriteObject(); // write out the ignoreCase flag
         s.writeInt(attrs.size());
         Enumeration<Attribute> attrEnum = attrs.elements();
@@ -295,10 +299,19 @@
     }
 
     /**
-     * Overridden to avoid exposing implementation details.
+     * Initializes the {@code BasicAttributes} from deserialized data.
+     *
+     * See {@code writeObject} for a description of the serial form.
+     *
+     * @param s the {@code ObjectInputStream} to read from
+     * @throws java.io.IOException if an I/O error occurs.
+     * @throws ClassNotFoundException if the class of a serialized object
+     *         could not be found.
      */
+    @java.io.Serial
     private void readObject(java.io.ObjectInputStream s)
             throws java.io.IOException, ClassNotFoundException {
+        // Overridden to avoid exposing implementation details.
         s.defaultReadObject();  // read in the ignoreCase flag
         int n = s.readInt();    // number of attributes
         attrs = (n >= 1)
--- old/src/java.naming/share/classes/javax/naming/ldap/LdapName.java	2020-08-25 15:53:57.866313394 +0100
+++ new/src/java.naming/share/classes/javax/naming/ldap/LdapName.java	2020-08-25 15:53:57.706316310 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -758,14 +758,29 @@
      * Serializes only the unparsed DN, for compactness and to avoid
      * any implementation dependency.
      *
-     * @serialData      The DN string
+     * @serialData The DN {@code String} representation of this LDAP name.
+     *
+     * @param s the {@code ObjectOutputStream} to write to
+     * @throws java.io.IOException if an I/O error occurs.
      */
+    @java.io.Serial
     private void writeObject(ObjectOutputStream s)
             throws java.io.IOException {
         s.defaultWriteObject();
         s.writeObject(toString());
     }
 
+    /**
+     * Initializes the {@code LdapName} from deserialized data.
+     *
+     * See {@code writeObject} for a description of the serial form.
+     *
+     * @param s the {@code ObjectInputStream} to read from
+     * @throws java.io.IOException if an I/O error occurs.
+     * @throws ClassNotFoundException if the class of a serialized object
+     *         could not be found.
+     */
+    @java.io.Serial
     private void readObject(ObjectInputStream s)
             throws java.io.IOException, ClassNotFoundException {
         s.defaultReadObject();
--- old/src/java.naming/share/classes/javax/naming/ldap/Rdn.java	2020-08-25 15:53:58.438302968 +0100
+++ new/src/java.naming/share/classes/javax/naming/ldap/Rdn.java	2020-08-25 15:53:58.278305884 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -735,14 +735,29 @@
      * Serializes only the unparsed RDN, for compactness and to avoid
      * any implementation dependency.
      *
-     * @serialData      The RDN string
+     * @serialData The unparsed RDN {@code String} representation.
+     *
+     * @param s the {@code ObjectOutputStream} to write to
+     * @throws java.io.IOException if an I/O error occurs.
      */
+    @java.io.Serial
     private void writeObject(ObjectOutputStream s)
             throws java.io.IOException {
         s.defaultWriteObject();
         s.writeObject(toString());
     }
 
+    /**
+     * Initializes the {@code Rdn} from deserialized data.
+     *
+     * See {@code writeObject} for a description of the serial form.
+     *
+     * @param s the {@code ObjectInputStream} to read from
+     * @throws IOException if an I/O error occurs.
+     * @throws ClassNotFoundException if the class of a serialized object
+     *         could not be found.
+     */
+    @java.io.Serial
     private void readObject(ObjectInputStream s)
             throws IOException, ClassNotFoundException {
         s.defaultReadObject();
--- old/src/java.naming/share/classes/javax/naming/spi/NamingManager.java	2020-08-25 15:53:59.014292469 +0100
+++ new/src/java.naming/share/classes/javax/naming/spi/NamingManager.java	2020-08-25 15:53:58.850295458 +0100
@@ -948,6 +948,10 @@
         return (answer != null) ? answer : obj;
     }
 
+    /**
+     * Thrown when an error is encountered while loading and instantiating the
+     * context factory classes.
+     */
     private static class FactoryInitializationError extends Error {
         @java.io.Serial
         static final long serialVersionUID = -5805552256848841560L;