GraphicalMapping: Split logic using user defined function

Hi all

I am doing a mapping in which the request xml comes this way

<header>                        ----- occurance 1
...............
</header>
<detail>                        ------- occurance 0 to unbounded
<F123ABC>1000</F123ABC>      ------- occurance 0 to 1
<F456PQR>2000</F456PQR>      ------- occurance 0 to 1
<G200XYZ></G200XYZ>      ------- occurance 0 to 1
<G500PPP>12</G500PPP>      ------- occurance 0 to 1
.................
</detail>    
<trailer>
..............
</trailer>

Now my target structure is like this

<zheader>                        ----- occurance 1
...............
</zheader>
<zdetail>                        ------- occurance 0 to unbounded
<record type>...............</<record type>
<Format>F</Format> ---if the tag <F123ABC> is not NULL then the data of format sortation and machine will be F,123 and ABC respectively and then whatever the between the TAG <F123ABC></F123ABC> will be fed in the *<quantity>*
<sortation>123<sortation>
<machine>ABC<machine>
<quantity>1000</quantity>
.................
</zdetail>    
<zdetail>                        ------- occurance 0 to unbounded
<record type>...............</<record type>
<Format>F</Format> ---if the tag <F456PQR> is not NULL then the data of format, sortation, and machine will be F,456 and PQR respectively and then whatever the between the TAG <F456PQR>2000</F456PQR>  will be fed in the *<quantity>*
<sortation>456<sortation>
<machine>PQR<machine>
<quantity>2000</quantity>
.................
</zdetail>    
<ztrailer>
..............
</ztrailer>

I tried this code in the UDF but it did not work

public void ud_splitDetail(String[] F123ABC,String[] F456PQR,String[] G200XYZ,String[] G500PPP,Detail,ResultList result,Container
   //write your code here
	int lenDetail=Detail.length;
	for(int i=0;i<lenDetail;i++)
	{
	//int len1=A.length;
	if(F123ABC<i>!=""){
	result.addValue("F");
	result.addContextChange();}

	if(F456PQR<i>!=""){
	result.addValue("F");
	result.addContextChange();
	}

	if(G200XYZ<i>!=""){
	result.addValue("F");
	result.addContextChange();
	}

	if(G500PPP<i>!=""){
	result.addValue("F");
	result.addContextChange();
	}
	
	else
	result.addValue("");
	result.addContextChange();
	}

The above code is to take F for format and the same way it is for sortation, machine and quantity

But this code is not working properly, it gives a lots of F and other values. Could anyone give me some idea of how to code for the desired output

Your help is really appreciable

Thanks

Naina