Confusion regarding autocommit

Hi

We have an application which used the jdbc 8.2-504 version. We have
recently tried to update it to 42.2.5 jre 7 version. During this update we
faced the issue "could not commit when autocommit is enabled" error so we
have decided to assign false to autocommit during connection initiation.
Now many of the SQL statements we use are select statements and we have
read from many sources that even select statements should be committed to
clear locks on tables. Is this necessary or is it ok to just close the
connection after the operations are done(for select statements only).

Thanks in advance