Hi, I would strongly suggest to do some profiling of your particular use-case first. Just starting some optimization might lead you in the wrong direction altogether. Only when you know where how much time is spent you can make an educated guess at where some change will actually provide an improvement.
Based on the results, we may be able to suggest things to make it run quicker or even be able to fix POI to do things in a better way altogether. Dominik. On Tue, Jul 5, 2016 at 7:21 PM, Blake Watson <blake.wat...@pnmac.com> wrote: > 1) Ensure I only save relevant sheets/cells from the files (to speed up > retrieval/parsing) > 2) Override parsing in XSSFWorkbook to avoid unnecessary work such as > themes, styles etc > 3) Pool the workbooks to avoid creating them every time (even though I need > to be able to update them separately for every request) > 4) Something else :-) > > I don't know about #1. Personally, I just save the output values, not the > sheets. > > #2 seems like a whole lot of work, especially compared to #3. > > #3 is what I do: Load the workbook on first request and re-use for > subsequent requests. If you know in advance what cells may be changed, you > can cache those values when you first load a workbook. Then you hand the > workbook out to a consumer, with the understanding that only those input > values are changed. When done you restore the inputs to their > original values. (And, in my case, I re-evaluate the workbook at that > point, to restore things as much as possible.) > > #4? Well, profiling is good. A lot of times you think your bottleneck is > one thing and it turns out to be something unexpected entirely. > > ===Blake=== > >
