Using a counter in addition with variable substitution

Question

Hi experts,
i'm having a problem where i can not find a nice 'standard' solution. I'm also not sure if it is possible what i want.
I'm using a receiver file adapter and sending a .CSV file. The naming convention of this file is: %delivery&-(counter).csv.
The filling of the delivery is no problem, also the counter is added. But i want the counter to continue counting. Let me explain what happens now.
Delivery 80000100 is sent by SAP R/3.
Generated file name: 80000100-0001.csv
Delivery 80000100 is sent again by SAP R/3 (a change). 
Generated file name: 80000100-0002.csv
Delivery 80000101 is sent by SAP R/3.
Generated file name: 80000101-0001.csv
In the last situation i do not want the 0001, but i want the 0003. Is this possible ?
Thanks in advance,
Peter

Answer 1

Hello peter,
We have implement exactly similar scenario.....
What we did is maintain the counter in a database table field. In the mapping use a dblookup to fetch the last number.. then carry out a function which will carry out dynamic config for filename set.. and then another db call to set the counter incrementing by one...
The code for setting filename by dynamic config is:
public String setFilename(String value,Container container){
//perform lookup
// Defining AbstractTrace object to write trace messages
AbstractTrace trace = container.getTrace();
//Dynamic file name
DynamicConfiguration conf = (DynamicConfiguration) container.getTransformationParameters().get(StreamTransformationConstants.DYNAMIC_CONFIGURATION);
DynamicConfigurationKey key = DynamicConfigurationKey.create("http://sap.com/xi/XI/System/File","FileName");
try{
trace.addInfo("Filename in set name: " + fileName);
//set file name
conf.put(key,fileName);
}catch(Exception e)
     trace.addInfo("Exception: " + e);
//return value as it is
return value;