mysql jdbc multi update return wrong affected rows

    String sql = "update t_test set createDate = now() where id = 1; update t_test set createDate = now() where id = 101;";
    String url = "jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai&zeroDateTimeBehavior=convertToNull&allowMultiQueries=true&useSSL=false";
    Connection connection = DriverManager.getConnection(url, "username", "password");
    connection.setAutoCommit(false);
    final PreparedStatement preparedStatement = connection.prepareStatement(sql);
    preparedStatement.execute();
    //return 1, but 2 rows actually updated
    System.out.println("updated rows=" + preparedStatement.getUpdateCount());
    connection.commit();
    connection.close();

table t_test contains two columns: id and createDate, I set allowMultiQueries=true in jdbc url.
In the above sql, two rows are updated, but preparedStatement.getUpdateCount() returns 1.
MySQL server version is 5.7, I have tested with jdbc driver version 5.1.40, 6.0.6 and 8.0.21, they all return same result:1

EDIT:
As @Massimo said, I use getMoreResults() and getUpdateCount() repeatedly to get updated count and sum them up until getUpdateCount() returns -1.

Code is below:

    System.out.println("updated rows=" + preparedStatement.getUpdateCount());
    int totalCount = preparedStatement.getUpdateCount();
    while (true){
        preparedStatement.getMoreResults();
        final int updateCount = preparedStatement.getUpdateCount();
        if(updateCount != -1){
            System.out.println("updated rows=" + preparedStatement.getUpdateCount());
            totalCount += preparedStatement.getUpdateCount();
        }else{
            break;
        }
    }
    System.out.println("total updated rows=" + totalCount);

Cannot test it.
However in theory, as you are executing multiple statements, the preparedStatement gets back the updateCount of each one.
So it's giving the update count of the first statement. To get the update count of the second you should try calling preparedStatement.getMoreResults() and then preparedStatement.getUpdateCount() again.

see docs

https://docs.oracle.com/javase/7/docs/api/java/sql/Statement.html#getUpdateCount()

https://docs.oracle.com/javase/7/docs/api/java/sql/Statement.html#getMoreResults()