[Java] Support Dictionary Encoding for binary type #22254
Description
Now is not implemented because byte array is not supported to be HashMap key.
One possible way is that wrap them with something to implement equals and hashcode.
Reporter: Ji Liu / @tianchen92
Assignee: Ji Liu / @tianchen92
PRs and other links:
Note: This issue was originally created as ARROW-5835. Please see the migration documentation for further details.