Prd

PrdAggregate 实现了乘积聚合。

类定义

    public static class PrdAggregate implements Aggregate<Number>
    {
        public void initialize(Number val) 
        {
            prd = val.doubleValue();
        }
 
        public void accumulate(Number val) 
        {
            prd *= val.doubleValue();
        }
         
        public Object result() 
        {
            return new Double(prd);
        }
         
        public void merge(Aggregate<Number> other) 
        {
            prd *= ((PrdAggregate)other).prd;
        }
 
        double prd;
    }