Freeing resources v42.5.4.2

Every JDBC object consumes resources. A ResultSet object, for example, might contain a copy of every row returned by a query. A Statement object might contain the text of the last command executed. It’s usually a good idea to free up those resources when the application no longer needs them. The sample application releases the resources consumed by the Result, Statement, and Connection objects by calling each object’s close() method:

rs.close();
stmt.close();
con.close();

If you attempt to use a JDBC object after closing it, that object returns an error.