Re: Database helper class with PreparedStatements
On Nov 10, 6:04 pm, Lew <l...@lewscanon.com> wrote:
tes...@hotmail.com wrote:
Thanks for info. I combined the classes and was wondering if this is
more efficient?
public class DbWork
{
private Connection connection = new
ConnectionMgr().getConnection();
private PreparedStatement stat;
There are consequences to making the connection happen at construction time
and making 'connection' and 'stat' instance variables.
public void cityInserter(FormBean city) throws SQLException
{
stat = connection.prepareStatement("Insert into City (street,
school) values (?,?)");
stat.setString(1, city.getStreet());
stat.setString(2, city.getSchool());
stat.executeUpdate();
}
.......
It's better to leave the sample code compilable than to throw in this kind of
ellipsis.
public dbMethod(FormBean city)
You need a return type such as 'void' for a method.
{
try
{
cityInserter(city);
}
catch(SQLException ex)
{
System.out.println(ex);
}
finally
{
connection.close();
The problem here is that connection is part of the instance, and created
during construction, but you close() it before the object is disposed. This
leaves the possibility of client code attempting to re-use the object after
the connection has been closed.
}
}
......
<http://www.physci.org/codes/sscce.html>
}
--
Lew
Thanks for your quick response.
Would this be better where I put the Connection and PreparedStatement
instances in the method??
public class DbWork
{
public void cityInserter(FormBean city) throws SQLException
{
Connection connection = ConnectionMgr().getConnection();
PreparedStatement stat
stat = connection.prepareStatement("Insert into City
(street,
school) values (?,?)");
stat.setString(1, city.getStreet());
stat.setString(2, city.getSchool());
stat.executeUpdate();
}
public void dbMethod(FormBean city)
{
try
{
cityInserter(city);
}
catch(SQLException ex)
{
System.out.println(ex);
}
finally
{
connection.close();
//not sure if I corrected this issue here or not??
The problem here is that connection is part of the instance, and created
during construction, but you close() it before the object is disposed. This
leaves the possibility of client code attempting to re-use the object after
the connection has been closed.
}
}