| RDS 2.5 API Reference |  |
Handler Property Example (VJ++)
This example demonstrates the RDS DataControl object Handler property. (See DataFactory Customization for more details.)
Assume the following sections in the parameter file, Msdfmap.ini, located on the server:
[connect AuthorDataBase] Access=ReadWrite Connect="DSN=Pubs" [sql AuthorById] SQL="SELECT * FROM Authors WHERE au_id = ?"
Your code looks like the following. The command assigned to the SQL property will match the AuthorById identifier and will retrieve a row for author Michael O'Leary. Although the Connect property in your code specifies the Northwind data source, that data source will be overwritten by the Msdfmap.ini connect section. The DataControl object's Recordset property is assigned to a disconnected Recordset object purely as a coding convenience.
// BeginHandlerJ
import com.ms.wfc.data.*;
import com.ms.wfc.data.rds.*;
import java.io.* ;
public class HandlerX
{
// The main entry point for the application.
public static void main (String[] args)
{
HandlerX();
System.exit(0);
}
// HandlerX function
static void HandlerX()
{
// Define ADO Objects.
Recordset rstAuthors = null;
// Declarations.
BufferedReader in =
new BufferedReader (new InputStreamReader(System.in));
int intCount = 0;
int intDisplaysize = 15;
try
{
IBindMgr dc = (IBindMgr) new DataControl();
dc.setServer("MyServer");
dc.setConnect("Data Source=Northwind");
dc.setSQL("AuthorById(267-41-2394)");
dc.Refresh(); // Retrieve the record.
// Use another recordset as a convenience.
rstAuthors = (Recordset)dc.getRecordset();
System.out.println("Author is '" +
rstAuthors.getField("au_fname").getString() +
" " +
rstAuthors.getField("au_lname").getString() +
"'");
System.out.println("\nPress <Enter> to continue..");
in.readLine();
}
catch( AdoException ae )
{
// Notify user of any errors that result from ADO.
// As passing a Recordset, check for null pointer first.
if (rstAuthors != null)
{
PrintProviderError(rstAuthors.getActiveConnection());
}
else
{
System.out.println("Exception: " + ae.getMessage());
}
}
// System read requires this catch.
catch( java.io.IOException je)
{
PrintIOError(je);
}
catch(java.lang.UnsatisfiedLinkError e)
{
System.out.println("Exception: " + e.getMessage());
}
catch(java.lang.NullPointerException ne)
{
System.out.println(
"Exception: Attempt to use null where an object is required.");
}
finally
{
// Cleanup objects before exit.
if (rstAuthors != null)
if (rstAuthors.getState() == 1)
rstAuthors.close();
}
}
// PrintProviderError Function
static void PrintProviderError( Connection Cnn1 )
{
// Print Provider errors from Connection object.
// ErrItem is an item object in the Connection’s Errors collection.
com.ms.wfc.data.Error ErrItem = null;
long nCount = 0;
int i = 0;
nCount = Cnn1.getErrors().getCount();
// If there are any errors in the collection, print them.
if( nCount > 0);
{
// Collection ranges from 0 to nCount - 1
for (i = 0; i< nCount; i++)
{
ErrItem = Cnn1.getErrors().getItem(i);
System.out.println("\t Error number: " + ErrItem.getNumber()
+ "\t" + ErrItem.getDescription() );
}
}
}
// PrintIOError Function
static void PrintIOError( java.io.IOException je)
{
System.out.println("Error \n");
System.out.println("\tSource = " + je.getClass() + "\n");
System.out.println("\tDescription = " + je.getMessage() + "\n");
}
}
// EndHandlerJ
See Also
DataControl Object (RDS) | Handler Property (RDS)