src/java.base/share/classes/java/net/InetSocketAddress.java

@@ -134,10 +134,11 @@
         }
     }
 
     private final transient InetSocketAddressHolder holder;
 
+    @java.io.Serial
     private static final long serialVersionUID = 5076001401234631237L;
 
     private static int checkPort(int port) {
         if (port < 0 || port > 0xFFFF)
             throw new IllegalArgumentException("port out of range:" + port);

@@ -257,15 +258,17 @@
     /**
      * @serialField hostname String
      * @serialField addr InetAddress
      * @serialField port int
      */
+    @java.io.Serial
     private static final ObjectStreamField[] serialPersistentFields = {
          new ObjectStreamField("hostname", String.class),
          new ObjectStreamField("addr", InetAddress.class),
          new ObjectStreamField("port", int.class)};
 
+    @java.io.Serial
     private void writeObject(ObjectOutputStream out)
         throws IOException
     {
         // Don't call defaultWriteObject()
          ObjectOutputStream.PutField pfields = out.putFields();

@@ -273,10 +276,11 @@
          pfields.put("addr", holder.addr);
          pfields.put("port", holder.port);
          out.writeFields();
      }
 
+    @java.io.Serial
     private void readObject(ObjectInputStream in)
         throws IOException, ClassNotFoundException
     {
         // Don't call defaultReadObject()
         ObjectInputStream.GetField oisFields = in.readFields();

@@ -294,10 +298,11 @@
                                                                 oisAddr,
                                                                 oisPort);
         UNSAFE.putReference(this, FIELDS_OFFSET, h);
     }
 
+    @java.io.Serial
     private void readObjectNoData()
         throws ObjectStreamException
     {
         throw new InvalidObjectException("Stream data required");
     }