This question already has answers here:
How to load a large xlsx file with Apache POI?
(8 answers)
Closed 2 years ago.
Is there a way to use WorkbookFactory with big Excel file? (5,5 MB)
Workbook wb = WorkbookFactory.create(new FileInputStream(file));
when the file became big, by using background-colors."
I get the error: java.io.IOException: GC overhead limit exceeded.
Altering the excel is not an option.
Is it possible to ignore the styles when reading the excel?
side info: The background was changed for a lot of rows that don't contain text.
Here is the answer to your question:
Writing
For writing very huge files, there is SXSSFWorkbook which allows to do a streaming write of data out to files (with certain limitations
on what you can do as only parts of the file are held in memory).
Reading
For reading very huge files, take a look at the sample XLSX2CSV which shows how you can read a file in streaming fashion (again with
some limitations on what information you can read out of the file, but
there are ways to get at most of it if necessary).
Related
Excel allows around 65K records in a .xls file.
For more data, I am using .xlsx file .
I used HSSF previously and now using XSSF for reading this xlsx in java.
Now my question is, when I save data in .xls (<65K ) and run with HSSF I am able to
and when storing it in .xlsx and reading with XSSF(<65K still) my program throws out of heap memory.
Want to know if it's even possible because I verified it multiple times.
What I also observed the same data as xls has file size 19MB and as xlsx as 16MB
still reading xls doesn't throw memory issue but xlsx does.
Any idea how to solve it
ans what might be the reason causing this behaviour.
I have tried changing multiple sizes from 1024M to 4096M
It either fails to create a VM with given size or throws out of heap space.
Why is it specifically for xlsx read and not when xls read.
This question already has answers here:
How to read and write excel file
(22 answers)
Closed 6 years ago.
could you please anyone assist me how to read excel files datas and write into csv file using java????
Please give Code for this scenario
Thanks in Advance
Regards
Kumar
One simple solution would be to convert your excel file into a .CSV file by saving it as such. Then you could, depending on the excel table structure, read the CSV file if the table successfully saved as one.
I think reading a simple CSV-file in Java won't require any sample-coding from me since it is fairly simple if one understands the I/O operations of the Java API.
If you actually need to do that converting manually I would not go for Java here. Use VBA which is used for macro programming in Excel.
This question already has answers here:
Error While Reading Large Excel Files (xlsx) Via Apache POI
(4 answers)
Closed 7 years ago.
I am attempting to open a fairly large excel document (about 150,000 rows of 6 columns) using Apache POI in Java to remove an entire worksheet. When I try
wb = new XSSFWorkbook("OUTPUT/BOSS.xlsx");
I get
Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
I am really not sure what else to do. Unfortunately the server I am trying to do this on is running 1.5 so I am limited on what I can use/do. Also apparently SXSSF only works for writing, not reading, files.
Does anyone have some sort of suggestion as to what I might be able to use/try?
EDIT: The excel file is about 2.5mb if that matters
It seems the best way to parse the data from the excel document is to use POI SAX Parser. You can find more information on it here: http://poi.apache.org/spreadsheet/how-to.html#xssf_sax_api
The problem I have now is how to use this to then delete the worksheet that is being parsed. I will make a new question for this if I cannot figure it out.
This is a very challenging task to me as i am doing pretty much R&D to get rid of OutOfMemroyError during conversion of XLSX to CSV and my excel file can have three sheets and each sheet with 60000 rows.
I used XSSF and SAX (Event API) recently since this approach consumes very less memory. However the Event API is triggering events only for things actually stored within the file and this can be cause for me.
Earlier to this Event API approach, i used Workbook class to process XLSX file and eventually i am getting out of memory during this workbook creation provided below.
Workbook workbook = WorkbookFactory.create(new File("myfile.xlsx"));
so, what is the best way to process large volume of XLSX data with apache POI?
Here is an example for reading a large xls file using sax parser. Sax parser will help you avoid OOM exceptions.
Error While Reading Large Excel Files (xlsx) Via Apache POI
This question already has an answer here:
Closed 11 years ago.
Possible Duplicate:
How to write to the SAME excel sheet using JXL API?
i am reading one excel file and validating the same. If validation is not success, i want to display some error on the same sheet. So how it can be possible? Can any one have any idea?
I guess the only way is to create a temporary file of the original file and read the temporary file. Do the validations. Open the original file for writing and display the error message. Finally delete the temporary file :-)