[Linux dev] Re: Java NullPointerException

[Kobus Grobler <kobus@xxxxxxxxxx>]

Should be something like this:

ResultSet rs = null;
 try
 {
 	CallableStatement cs = conn.prepareCall("{call GetUserByName(?)}");
 	cs.setString(1, name);
 	rs = cs.executeQuery();
	 while(rs.next())
	 {
	 	// Do Stuff
	 }
 }
 catch(SQLException ex)
 {
 	System.out.println("ERROR getting user");
 	System.out.println(ex.getMessage());
 }
finally
{
 if (rs != null)  // cause what happens if rs is null (statement
failed)?
  rs.close();
}

even better would be to split it up (where do you close the statement?),
but it's a bit more typing.

CallableStatement cs = null;
try
{
	cs = conn.prepareCall("{call GetUserByName(?)}");
}
catch()
{
 //log error and leave procedure here
 return;
}

try
{
  rs = cs.executeQuery();
}
catch()
{
 //log error and leave procedure here
 return;
}
finally
{
   cs.close();
}

try
{
  while(rs.next())
  {
  	// Do Stuff
 }
}
catch()
{
 //log error and leave procedure here
 return;

}
finally
{
 rs.close();
 cs.close();
}

etc...

> 
On Thu, 2003-02-20 at 16:04, Jarrod Hermer wrote:
> Hi all,
> 
> I have a strange bug which I can't seem to pin down. Using Java 1.4.1 I
> have a simple app that polls a MS SQL server for data using a stored
> procedure here is my code:
> 
> ------------------------------------------------------------------------
> ----
> 
> ResultSet rs = null;
> 
> try
> {
> 	CallableStatement cs = conn.prepareCall("{call
> GetUserByName(?)}");
> 	cs.setString(1, name);
> 	rs = cs.executeQuery();
> }
> catch(SQLException ex)
> {
> 	System.out.println("ERROR getting user");
> 	System.out.println(ex.getMessage());
> }
> 
> while(rs.next())
> {
> 	// Do Stuff
> }
> rs.close();
> 
> ------------------------------------------------------------------------
> ----
> 
> On my development machine it functions without any problems. However on
> my production machine which I am convinced is identical the program
> crashes with a Java.NullPointerException error.
> 
> Any ideas?
> 
> Regards,
> Jarrod
> 
>