[ARROW-8665] [Java] DenseUnionWriter#setPosition fails with NullPointerException

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 0.17.0
• Component/s: Java
• External issue URL: https://github.com/apache/arrow/issues/24825
• Assignee: Unassigned
• Reporter: David Li
• Created: 01/May/20 17:30
• Updated: 11/Jan/23 08:01

Description

The writer always iterates through all BaseWriters, and an array of 128 BaseWriters is allocated. So if you do not have 128 typeIds and do not touch all of them, setPosition will give you an exception.