Java database connection security shutdown Code implementation

IF (conn! = null) {
   try {
    Conn.close ();
   } catch (Exception e) {
    E.printstacktrace ();
   }
   conn = null;
  }
Writing a tool class to close can also:
public static void Close (Connection conn) {
  IF (conn! = null) {
   try {
    Conn.close ();
   } catch (Exception e) {
    E.printstacktrace ();
   }
   conn = null;
  }
}
Note that there are functions that return SQL-related objects do not close connection, such as ResultSet, statement, PreparedStatement, hehe return to connection, not to mention If connection is a couple of functions

, then close the functions after they have been called, and it's best to turn the connection off in the function!!