[ARROW-11483] [Java][C++][Integration] C++ integration test creates JSON files incompatible with Java

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0.0
• Component/s: C++, Integration, Java
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/18493
• Assignee: Antoine Pitrou
• Reporter: Antoine Pitrou
• Created: 03/Feb/21 16:04
• Updated: 11/Jan/23 08:20
• Resolved: 07/Feb/21 23:27

Description

The C++ arrow-json-integration-test runner always emits an empty children array for non-nested fields, but the Java JSON reader for some reason uses an inflexible tokenize-based parsing technique and refuses such files:
https://github.com/apache/arrow/blob/master/java/vector/src/main/java/org/apache/arrow/vector/ipc/JsonFileReader.java#L722-L740

Typically the error message is as follows:

Incompatible files
Expected END_OBJECT but got FIELD_NAME
16:30:12.557 [main] ERROR org.apache.arrow.tools.Integration - Incompatible files
java.lang.IllegalStateException: Expected END_OBJECT but got FIELD_NAME
	at org.apache.arrow.vector.ipc.JsonFileReader.readToken(JsonFileReader.java:779)
	at org.apache.arrow.vector.ipc.JsonFileReader.readFromJsonIntoVector(JsonFileReader.java:740)
	at org.apache.arrow.vector.ipc.JsonFileReader.read(JsonFileReader.java:219)
	at org.apache.arrow.tools.Integration$Command$3.execute(Integration.java:203)
	at org.apache.arrow.tools.Integration.run(Integration.java:118)
	at org.apache.arrow.tools.Integration.main(Integration.java:69)

Issue Links

• links to: GitHub Pull Request #9405