Mapping UDF

Question

Hey folks
I have a mapping issue:
It is IDOC to file scenario
A segment in IDOC repeats multiple times. I want to take a field of the first repeating segment and map it to a target field.
And i want to take afield of the last repeating segment and map to a target field.
Eg : E1EDPL1  
            GSB     100
      E1EDPL1
           GSB      200
      E1EDPL1
           GSB     300
Mapping logic 1 :
Take the first GSB ( Value: 100) and map to a target field.
Mapping logic 2 :
Take the last GSB(Value : 300) and map to a target field.
Guess we need to have a context java function which takes as an input an array of GSB and extract first and last GSB.
Need help with the java udf.
Thnx

Answer 1

A small correction
Here a is the GSB values.
cache parameter - context
1st udf
public void add(String[] a,ResultList result,Container container)
   //write your code here
result.addValue(a[0]);
GSB ---> add -
> tgt1
2nd udf
public void add1(String[] a,ResultList result,Container container)
//write your code here
int len = a.length -1;
result.addValue(a[len]);
GSB---> add1 -
>tgt2