initializes com.mysql.jdbc.TimeUtil.timeZoneMappings if needed (Connector/J 5.x)

[hiroyuki-sato]

Reviese #200

Accept com.mysql.cj.util.TimeUtil in addition to com.mysql.jdbc.TimeUtil
Connector/J changed TimeUtil class.

[dmikurube]

As far as I understand, com.mysql.jdbc.TimeUtil should load /com/mysql/jdbc/TimeZoneMapping.properties, and com.mysql.cj.util.TimeUtil should load /com/mysql/cj/util/TimeZoneMapping.properties, respectively, right?

Then, I'd suggest to...

• Make two more methods, for example, loadTimeZoneMappingsForComMysqlJdbcTimeUtil() for com.mysql.jdbc.TimeUtil, and loadTimeZoneMappingsForComMysqlCjUtilTimeUtil() for com.mysql.cj.util.TimeUtil.
• Change the existing loadTimeZoneMappings() to call them, such as :

    private void loadTimeZoneMappings() {
        try {
            loadTimeZoneMappingsForComMysqlJdbcTimeUtil();
        } catch (final ClassNotFoundException ex) {
            try {
                loadTimeZoneMappingsForComMysqlCjUtilTimeUtil();
            } catch (final ClassNotFoundException ex2) {
                ex2.addSuppressed(ex);
                throw new RuntimeException(ex2);
            }
        }
    }

[hiroyuki-sato]

I read the source carefully again.
loadTimeZoneMappings() method was introduced in cb78d86.
I think loadTimeZoneMappings is necessary if the TimeUtil class is com.mysql.jdbc.TimeUtil. (Connector/J 5.x)
Connector/J 8.x and above may not need this method. In fact, this PR works with Connector/J 8.x.

in:
  type: mysql
  host: localhost
  user: user
  password: pasas
  database: embulk_test
  table: test
  driver_path: /tmp/mysql-connector-j-8.4.0/mysql-connector-j-8.4.0.jar
out:
  type: stdout

[dmikurube]

Basically looks good with a couple of suggestions.

[dmikurube]

LGTM!

[hiroyuki-sato]

Thanks!