wsuppiger opened a new issue, #625: URL: https://github.com/apache/arrow-java/issues/625
Not sure if I am using this wrong, but I noticed `getNewFieldWriter` for the minorType `MAP` is returning a `UnionListWriter` instead of a `UnionMapWriter`. https://github.com/apache/arrow-java/blob/799d9fd45e36d962c7a7bae0f3903bb414062554/vector/src/main/java/org/apache/arrow/vector/types/Types.java#L722-L726 This leads to the issue of this code block throwing an error: ```java MinorType.MAP.getNewFieldWriter(myMapVector) writer.startMap() ``` Exception: ``` You tried to start a map key when you are using a ValueWriter of type UnionListWriter. java.lang.IllegalStateException: You tried to start a map key when you are using a ValueWriter of type UnionListWriter. at org.apache.arrow.vector.complex.impl.AbstractFieldWriter.key(AbstractFieldWriter.java:123) at org.apache.arrow.vector.complex.impl.UnionListWriter.key(UnionListWriter.java:69) ... ``` I believe this code can be easily fixed by just changing it to: ```java @Override public FieldWriter getNewFieldWriter(ValueVector vector) { return new UnionMapWriter((MapVector) vector); } ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@arrow.apache.org.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
