NullPointerException when importing from delimited file and quickly changing the Import File Parser option

Prerequisites

• Put an X between the brackets on this line if you have done all of the following:
  • Running the latest version of Constellation
  • Attached the Support Package via Help > Support Package
  • Checked the FAQs: https://github.com/constellation-app/constellation/wiki/FAQ
  • Checked that your issue isn’t already filed: https://github.com/constellation-app/constellation/issues
  • Checked that there is not already a module that provides the described functionality: https://github.com/constellation-app/constellation/wiki/Catalogue-of-Repositories

Description

A NullPointerException occurs when you quickly change the Import File Parser option from the dropdown menu after opening the component for importing from delimited file.

Steps to Reproduce

1. Open clean build of Constellation.
2. File > Import > From Delimited File…
3. Select any other option from the dropdown menu for Import File Parser.

Expected behaviour: Any new Import File Parser option is selected without a NullPointerException occurring.

Actual behaviour: NullPointerException occurs.

Reproduces how often: 100%

Additional Information

The issue lies in RunPane.java at the top of the constructor at line 140, where the thread is not being returned in time for the dropdown menu and so a NullPointerException occurs.

(GIF of issue being reproduced will be added here)

[serpens24]

@arcturus2 - as discussed, the problem relates to the changes made in https://github.com/constellation-app/constellation/pull/847

What is occuring is that in some cases if you start trying to import a file using the dialog too soon the rowFilter member has not yet been set.

It may be worth backing out this change for the time being ?

Edit, the following code seemd to avoid the issue for me: if (rowFilter == null) { rowFilter = new RowFilter(); // new Thread(() -> { // rowFilter = new RowFilter(); // }, ROW_FILTER_INITIALISER).start(); }

basically performing the rowFilter = new RowFilter() in the current thread rather than a new thread.

Note, my change above has no improvement over the original code that was fixed in the mentioned pull requesat. A quick stopwatch comparison indicated that it takes about 7 seconds to open the dialog (the first time) without the pull request changes. This also suggests that its within this seven seconds (roughly) that the user needs to try and open a file to cause the exception.

‘Maybe’ two ideas to investigate are:

1. Only enable to open (+) icon once the rowFilter member is set, or
2. investigate why creating a new RowFilter takes so long.

[antares1470]

I believe this is done as I tested removing some null checks for rowFilter (that wouldn’t have been present when this issue was created) and was able to get the exception following the reproducer. Couldn’t get it happen with the null checks in place