Report export one million data
demand analysis
Use Apache POI to complete the amount of one million data export Excel reports
solution
Ideas analysis
Based XSSFWork export Excel reports, is by saving all cell object into memory, when all the cells in Excel all the write-once created and exported to Excel. When the one million level Excel data export, with the creation of the table, more and more objects in memory until the memory overflow. Apache Poi provides SXSSFWork objects, specifically for large volume data processing Excel report export.
Principle Analysis
When the number of instances of this object SXSSFWork, can be specified in the generated memory related objects derived POI (default 100), once the number of objects in memory reaches the predetermined value, these will be the contents of memory objects written to disk (XML file format), it can destroy these objects from memory, since as long as this value is reached, will be handled in a similar way to deal with until the Excel export is completed.
