Driver version

mssql-jdbc-8.4.0.jre11.jar

SQL Server version

Microsoft SQL Server 2017 (RTM-GDR) (KB4505224) - 14.0.2027.2 (X64) Jun 15 2019 00:26:19 Copyright (C) 2017 Microsoft Corporation Developer Edition (64-bit) on Windows Server 2016 Standard 10.0 (Build 14393: ) (Hypervisor)

Client Operating System

Windows 10

JAVA/JVM version

RedHat OpenJDK
openjdk version "11.0.8" 2020-07-14 LTS
OpenJDK Runtime Environment 18.9 (build 11.0.8+10-LTS)
OpenJDK 64-Bit Server VM 18.9 (build 11.0.8+10-LTS, mixed mode)

Table schema

CREATE TABLE [dbo].[TEST](
	[name] [varchar](10) COLLATE Japanese_CS_AS_KS_WS NOT NULL
)

Problem description

1. Expected behaviour:
   One row has been bulk-inserted.

2. Actual behaviour:
   SQL Exception occured.

3. Error message/stack trace:
   Exception in thread "main" com.microsoft.sqlserver.jdbc.SQLServerException: (... (Japanese message))

4. Any other details that can be helpful:
   In SQLBulkCopy.java, Line Around 2292 (commit-id 4e3ab66):

2292: tdsWriter.writeShort((short) (colValueStr.length()));

I think the above code should be something like this:
tdsWriter.writeShort((short) (colValueStr.getBytes(destColumnMetadata.get(destColOrdinal).collation.getCharset()).length));
when destCollation is not null.
Because colValueStr.length() is different from the transferred byte size by tdsWriter.writeBytes();

Bulk.java.txt