I doubt that support of null values in the data model is intentional because JList is "A component that displays a list of *objects* and allows the user to select one or more items."

The null behavior was not specified and work in most cases because some of the getXXX methods in ListModel sub-classes and JList have a special meaning of null:

JList.getSelectedValue(): Returns {@code null} if there is no selection.
ListModel.getElementAt(int index): In most cases implemented to return null if index is incorrect.

Similar method TableModel.getValueAt(int,int) is also usually implemented to return null if value is not found or some error occured.

JComboBox.setSelectedItem(): use <code>null</code> to clear the selection
ComboBoxModel.setSelectedItem(): <code>null</code> to clear the selection
ComboBoxModel.getSelectedItem(): <code>null</code> if there is no selection

So I suggest to follow initial intention here, because it is too late to add validation of the values.
 - The null value in get() will mean no-selection.
 - The null value passed to set() will clear selection.

On 05/01/2018 02:15, Pankaj Bansal wrote:
Hi Semyon/Sergey,

Yes, JList can contain null elements as it can be added to data model. I think 
this changes a lot in this bug. I think the selection needs to be cleared when 
the object passed is not present in the list, irrespective of it being null or 
not. I have made code changes. Please have a look.

Webrev: http://cr.openjdk.java.net/~pbansal/5076761/webrev.02/

Regards,
Pankaj Bansal

-----Original Message-----
From: Semyon Sadetsky
Sent: Friday, January 5, 2018 6:59 AM
To: Pankaj Bansal; swing-dev@openjdk.java.net
Subject: Re: <Swing Dev> [11] Review Request: JDK-5076761 : 
JList.setSelectedValue(null, ...) doesn't do anything

Hi Pankaj,

Can JList contain null value?

--Semyon


On 01/02/2018 11:26 PM, Pankaj Bansal wrote:
Hi Sergey,

Thanks for the review.

I have made the suggested changes. Please have a look.
webrev: http://cr.openjdk.java.net/~pbansal/5076761/webrev.01/

Regards,
Pankaj Bansal


-----Original Message-----
From: Sergey Bylokhov
Sent: Wednesday, January 3, 2018 3:31 AM
To: Pankaj Bansal; swing-dev@openjdk.java.net; Prasanta Sadhukhan
Subject: Re: [11] Review Request: JDK-5076761 :
JList.setSelectedValue(null, ...) doesn't do anything

Hi, Pankaj.
The fix looks fine, but I suggest to update the spec as well and describe the behavior if 
"null" value is passed.

On 02/01/2018 02:07, Pankaj Bansal wrote:
Hi All,

Please review the fix for JDK 11.

Bug:

https://bugs.openjdk.java.net/browse/JDK-5076761

Webrev:

http://cr.openjdk.java.net/~pbansal/5076761/webrev.00/

Issue:

When setSelectedValue is called on JList with null object, it should
clear all selection. But it is not doing anything.

Fix:

In setSelectedValue if the object is null, the setSelectedIndex is
called with -1. but this does not clear the selection. We should be
calling clearSelection instead of SetSelectedIndex.

Regards,

Pankaj Bansal


--
Best regards, Sergey.



--
Best regards, Sergey.

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