RFR: 4938801: The popup does not go when the component is removed [v6]

[Prasanta Sadhukhan]

On Wed, 30 Jul 2025 04:41:41 GMT, Jeremy Wood <duke at openjdk.org> wrote:

>> It is transient so  its value should not be included in the default serialization process in my opinion
>
> I'm fine with `propListener` being transient ... as long as when we call readObject() we still initialize `propListener`.
> 
> Here's a unit test that demonstrates what I'm worried about:
> 
> import javax.swing.*;
> import java.beans.PropertyChangeListener;
> import java.io.*;
> 
> public class JPopupMenuSerializationTest {
>     static class JPopupMenuSubclass extends JPopupMenu implements Serializable {
>         private transient PropertyChangeListener propListener =
>                 (e) -> {
>                     if (e.getOldValue() != null
>                             && e.getNewValue() == null
>                             && isVisible()) {
>                         setVisible(false);
>                     }
>                 };
> 
>         @Serial
>         private void writeObject(ObjectOutputStream s) throws IOException {
>             Object serializable = propListener instanceof Serializable ?
>                     (Serializable) propListener : null;
>             System.out.println("Serialized: " + serializable);
>             s.writeObject(serializable);
>         }
> 
>         @Serial
>         private void readObject(ObjectInputStream s)
>                 throws IOException, ClassNotFoundException {
>             PropertyChangeListener l = (PropertyChangeListener) s.readObject();
>             System.out.println("Deserialized: " + l);
>             if (l != null) {
>                 propListener = l;
>             }
>             System.out.println("propListener: " + propListener);
>         }
>     }
> 
>     public static void main(String[] args) throws Exception {
>         JPopupMenuSerializationTest test = new JPopupMenuSerializationTest();
>         test.testSerialization();
>     }
> 
>     public void testSerialization() throws Exception {
>         JPopupMenuSubclass popupMenu = new JPopupMenuSubclass();
>         byte[] data = serialize(popupMenu);
>         JPopupMenuSubclass copy = deserialize(data);
> 
>         assertTrue("original.propListener should exist", popupMenu.propListener != null);
> 
>         // currently this fails, and IMO it should pass:
>         assertTrue("copy.propListener should exist",  copy.propListener != null);
>     }
> 
>     private static void assertTrue(String errorMsg, boolean b) {
>         if (!b)
>             throw new Error(errorMsg);
>     }
> 
>     private static byte[] serialize(JPopupMenuSubclass popupMenu) throws IOException {
>         try (ByteArrayOutputStream byteOut = new ByteArrayOutputStream()) {
>             try (ObjectOutputStream objOut = new ObjectOutputStream(byteOut)) {
>                 objO...

Hmm..We need to take a look at how to handle serialization aspect of propListener

but as per https://docs.oracle.com/javase/tutorial/java/javaOO/lambdaexpressions.html#serialization


> You can serialize a lambda expression if its target type and its captured arguments are serializable. However, like inner classes, the serialization of lambda expressions is strongly discouraged.

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PR Review Comment: https://git.openjdk.org/jdk/pull/26407#discussion_r2241547175