As a side note, beware of direct use of user-supplied data in SQL; it makes
your code potentially vulnerable to "SQL injection" attacks.  Here your
variable 'id' is apparently an int that was not from user-supplied input, and
thus might be immune, but consider

String sql = "SELECT * FROM authtable WHERE user = '"
  + userSuppliedUser
  +"' AND pw = '"+ userSuppliedPw +"'";

This represents a common antipattern to authorize a user via a SQL statement.

If the user-supplied 'user' were
  "anything' AND 1=1 -- "

and the 'password' were "something", then the resulting SQL would be

SELECT * FROM authtable
    WHERE user = 'anything' AND 1=1 -- ' AND pw = 'something'

which would return the entire authtable.

Actual attacks would be somewhat more sophisticated, but this shows the
essential principle.  Better would be to use a PreparedStatement:

String sql =
"select host,port,username,password,LastCrawlState "
+"from HostTable where id =?";

PreparedStatement stmt = con.prepareStatement( sql );
stmt.setInt( 1, id );
rs = stmt.executeQuery();

Even in your case, where user-supplied input is not an issue, if you repeat
the query with different 'id' values then a PreparedStatement is likely to
give you a performance boost.  You would prepare the statement only once, then
repeat only the stmt.setInt() before each different query.

- Lew