How to avoid a method to be called multi times

[Chuangyu]

Hi,
I create a defaultXXX method,in this method it fetchs a sequence number
like below

public Integer default0NewMaintainRequest(){
SequenceGenerator seq=seqGens.findGenerator();
Integer n=seq.getSequnceNumber();
n++;
                seq.setSequenceNumber(n);
 return n;
}

But it was called 2 times when invoke newMaintainRequest(Integer
code.....), and sequence number was plus 2  every time.

How can I avoid this behavior ?