I'm developing a JFreeChart, which will do some calculation after I get the data from database. Since I need the X Aixs range selectable, so anytime I change the selection, the program will fetch the data again, and do the same calculation again. It really waste time I think.
So, to aware in the chart development is the performance.
Since the data does not change much. I want to add use a hash table to store the results so that the data can be reused. But don't know how to make it , any advise from your guys ? thanks.