Bug 50320

Summary: Opening .xlsx file cosumes large memory space
Product: POI Reporter: chentao <chentao106>
Component: XSSFAssignee: POI Developers List <dev>
Severity: normal    
Priority: P2    
Version: 3.7-FINAL   
Target Milestone: ---   
Hardware: PC   
OS: Windows Server 2003   

Description chentao 2010-11-22 23:01:06 UTC

When I open a .xlsx file in POI is see a lot of instance of class org.apache.xmlbeans.impl.store.Xobj. 
They take up a large space in the JVM( compare to the .xls file ).
Is it a bug in the memory usage when parsing OOXML files?
Or it is just a different in the implementation when parsing old and new excel files?
Comment 1 Nick Burch 2010-11-23 07:06:24 UTC
The XSSF UserModel needs more memory than the equivalent HSSF one, because it's XML based rather than records, and that uses more. If memory is a real issue, you'll want to do SAX based processing. http://poi.apache.org/spreadsheet/how-to.html#xssf_sax_api details how