The interview asked how to optimize excel The problem of loading data too slowly , Deep study excel Read and write , There are two solutions ：Apache Of POI And Alibaba open source easyExcel

POI Official website ：https://poi.apache.org/

easyExcel Official website ：easyexcel: easyexcel —— JAVA analysis Excel Tools Java analysis 、 Generate Excel Well known frameworks are Apache poi、jxl

The source code has been put on the code cloud , Self access required ： Geng Hongbo /POITest

100 Ten thousand data test writing basically only needs 8 second , Reading may require 18 About seconds .

1.POI

1.1 POI Write read test

POIWriteTest altogether 5 A way ：
writeTest：03 Version write test 
write07Test:07 Test version 
write03BigDataTest:03 Version large data write test 
write07BigDataTest:07 Version large data write test 
write07BetterBigDataTest:07 Version large data write test - Optimized version 

POIReadTest： And POI Write class correspondence 

2.EasyExcel

2.1 EasyExcel Write read test

easyExcel The principle of is equivalent to POI The data that needs to be loaded into memory at one time only needs to be segmented , Multiple loads and writes , There is no guarantee that OOM The situation of , But the test only supports xlsx file .