[ARROW-612] [Java] Field toString should show nullable flag status

• Type: Improvement
• Status: Resolved
• Priority: Trivial
• Resolution: Fixed
• Fix Version/s: 0.3.0
• Component/s: Java
• External issue URL: https://github.com/apache/arrow/issues/16241
• Assignee: Bryan Cutler
• Reporter: Bryan Cutler
• Created: 10/Mar/17 22:36
• Updated: 11/Jan/23 07:09
• Resolved: 12/Mar/17 17:50

Description

Often when comparing Schemas, I'll see an error message like below because of differing schemas. The only difference is one is nullable and one is not, but that info is not printed in the Field.toString method.

 - numeric type conversion *** FAILED *** (118 milliseconds)
[info]   java.lang.IllegalArgumentException: Different schemas:
[info] Schema<i: Int(32, true)>
[info] Schema<i: Int(32, true)>
[info]   at org.apache.arrow.vector.util.Validator.compareSchemas(Validator.java:43)

I would be nice to match the C++ Field.toString that prints " not null " only if the nullable flag is not set. Which would then look like this

[info] Schema<i: Int(32, true) not null>
[info] Schema<i: Int(32, true)>