add BigDecimal in order to have a running total

Question

I would like to pick your brians about BigDecimal.. I have a method which is supposed to have a add up a running total amount due. here it is:

private BigDecimal addUpTotal(BillRec bill, BigDecimal runningTotal) {
    BigDecimal result = new BigDecimal(0);

    if (bill.getBillInfo().getBillSummAmtSize() > 0) {
        for (int x = 0; x < bill.getBillInfo().getBillSummAmtSize(); x++) {
            if ("TotalAmtDue".equals(bill.getBillInfo().getBillSummAmt(x).getBillSummAmtCode().getCode().toString())) {
                result = runningTotal.add(bill.getBillInfo().getBillSummAmt(x).getAmt());                  
            }
        }
    }      
    return result;
}

the problem is how do I call this? meaning when I call it how do I keep track of the total? Note as you can see I am passing the runningTotal as a param but not sure how to keep the value in the method I would call this from.

Answer 1

I suspect you meant it to be something like this:

private BigDecimal addUpTotal(BillRec bill, BigDecimal runningTotal) {
    if (bill.getBillInfo().getBillSummAmtSize() > 0) {
        for (int x = 0; x < bill.getBillInfo().getBillSummAmtSize(); x++) {
            if (...) {
                runningTotal = runningTotal.add(...);
            }
        }
    }      
    return runningTotal;
}

You'd call that using a local variable to keep the running total:

BigDecimal runningTotal = BigDecimal.ZERO;

for (BillRec bill : bills) {
    runningTotal = addUpTotal(bill, runningTotal);
}