Develop Reference

Keeping Pivot Table and Formating intact in JExcel

I am trying to write data to an excel sheet using JExcel. I have an excel file placed on disk and I opened it using JExcel and then created a Writable Workbook.
The Excel workbook contains sheets having pivot table. Idea is to just populate source sheets and then refresh the pivot tables. But after creating Writable Workbook, the formatting and pivot tables got away.
Here is my code snippet:
FileInputStream fileInputStream = new FileInputStream("C:\\Pivot_File_template.xls");
workbook = Workbook.getWorkbook(fileInputStream);
WorkbookSettings workbookSettings = new WorkbookSettings();
writableWorkbook = Workbook.createWorkbook(new File("C:\\Writable_Pivot_File.xls"),workbook,workbookSettings);
The file "Writable_Pivot_File.xls" just lost the orignal formatting and pivot tables. Any suggestions what I can do to maintain all the formatting and pivot tables? I am using "jxl_2.6.9.jar". Thanks in advance.

Just got away with this issue by using Apache POI. JExcel doesnot support xlsx and updating an xls file having pivot table using JExcel will disable the Pivot table and change its formatting.

How to write to an existing file using SXSSF?

I have an .xlsx file with multiple sheets containing different data. Of all the sheets one sheet needs to accommodate close to 100,000 rows of data, and the data needs to be written using Java with poi.
This seems quite fast and simple with SXSSFWorkbook, where I can keep only 100 rows in memory, but the disadvantage is that I can only write to a new file (or overwrite existing file).
Also, I am not allowed to 'load' an existing file, i.e
SXSSFWorkbook wb = new SXSSFWorkbook(file_input_stream) is not allowed.
I can use Workbook factory:
Workbook workbook = new SXSSFWorkbook();
workbook = WorkbookFactory.create(file_input_stream);
but when the time comes for me to flush the rows,
((SXSSFSheet)sheet).flushRows(100);
I get the error that type conversion is not allowed from XSSFSheet to SXSSFSheet.
I tried to see if there was any way to copy sheets across different workbooks, but so far it seems it has to be done cell by cell.
Any insights on how to approach this problem?

You are probably having a template to which you want to add large data. You need to use the SXSSFWorkbook(XSSFWorkbook) constructor:
XSSFWorkbook wb = new XSSFWorkbook(new File("template.xlsx"));
SXSSFWorkbook wbss = new SXSSFWorkbook(wb, 100);
Sheet sheet = wbss.createSheet("sheet1");
// now add rows to sheet

Can not read .xlsm file - POI

I have written a code to access .xlsm file but it fails to do so. I have tried the same file using both XSSFWorkBook and the Generic WorkBook which is done using WorkBookFactory.
Scenario 1:
org.apache.poi.ss.usermodel.Workbook workbook = WorkbookFactory.create(new File(
"/filename.xlsm"));
Error:
The supplied spreadsheet seems to be an Encrypted .xlsx file. It must be decrypted before use by XSSF, it cannot be used by HSSF.
So I left the generic way of reading the file and used XSSF.
Scenario 2:
XSSFWorkbook workBook = new XSSFWorkbook(new FileInputStream(new
File("/fileName.xlsm")));
Error:
org.apache.poi.POIXMLException: org.apache.poi.openxml4j.exceptions.InvalidFormatException: Package should contain a content type part [M1.13]
Both the scenarios do work on some .xlsm files. Properties and data with working and non working files are the same.
Can someone help in fixing this.?

Promoting a comment to an answer... You need to upgrade your version of Apache POI!
You can view the Apache POI changelog here, and see quite how many changes there have been since 3.9 came out 3 years ago. It's quite a number of pages of fixes! And you need at least one of those...

Out of Memory Error - Java Heap Space while writing to Excel

I have a data of almost 100,000 records and I am trying to write the data to .xlsx file using XSSFWorkbook through Java code. I am able to fetch all the data from database to an ArrayList. By iterating the ArryList, I am writing the data to .xlsx file cell by cell.
As it reaches to 8000 rows, java code throws Out of Memory Heap Space Error.
I have read somewhere that SXSSFWorkbook will be lighter when compared to XSSFWorkbook, so I tried using SXSSFWorkbook. But still I am facing the same problem.
So is there anything that I am missing with the Workbooks or with my Java Code??
Initially, when I have 60,000 records data, I had used .xls file. The same java code is able to generate the .xls file with HSSFWorkbook.
Increasing the Java Heap Space is not at all an option as my data will be increased tremendously in future.
Any help will be greatly appreciated.
Small piece of code, the way I am writing the data to Excel.
int rowNum = sheet.getLastRowNum();
Row lastRow = null ;
Cell cell = null;
ReportingHelperVo reportingHelperVo = null;
for (ReportingVo reportingVo : reportingVos) {
rowNum++;
lastRow = sheet.createRow(rowNum);
reportingHelperVo = reportingVo.reportingHelperVo;
cell = lastRow.createCell(0);
cell.setCellValue(reportingHelperVo.getLocation());
cell.setCellStyle(style);
cell = lastRow.createCell(1);
cell.setCellValue(reportingHelperVo.getCity());
cell.setCellStyle(style);
cell = lastRow.createCell(2);
cell.setCellValue(reportingHelperVo.getCountry());
cell.setCellStyle(style);
}

SXSSFWorkbook is not like light weight,but there is a advantage with this.
If you declare as
SXSSFWorkbook workbook= new SXSSFWorkbook(200);
then for every 200 rows written on the workbook, memory will be flushed to diskspace so there will be no burden in heapspace.

XSSFWorkbook - creates an object representation for all Excel documents (should work like DOM).
SXSSFWorkbook - should require constant memory. When is OOM thrown by JMV? What type of ResultSet did you use? Try to use FORWARD_ONLY to restrict caching data by JDBC driver retrieved from DB.
BTW best weay to fix OutOfMemoryError is to analyze heap dump.
Use -XX:+HeapDumpOnOutOfMemoryError parameter and MAT to understand how your application works.

I am writing the data to .xlsx file cell by cell. As it reaches to
8000 rows, java code throws Out of Memory Heap Space Error.
Re-use exsiting java objects, instead of creating new ones each iteration.
And/or use a csv file instead of excel.

Workbook workBook = new SXSSFWorkbook();
You can export more than 1 lakh (100000) records.

Page results from the database rather than reading them all in one go.

I had similar problems long time ago attempting to write from R to an excel file (but using XLConnection).
In the end, I solved by using write.csv and then opening it with Excel and using the botton "Text to column".
It is increadibly fast and reliable.

I have got the same issue when my excel was reaching 3000 lines. In my case the main memory related issue with POI Excel generation happens with the style sheet. Following are the things which I removed from my code.
Try to use style sheet setting in a row level.
If at all you need to set the style sheet for every cell.. avoid setting border for each and every cell.

Hi Use latest Apache POI JAR//And Use SXSSF for streaming or downloading
SXSSFWorkbook workbook = new SXSSFWorkbook(100);
workbook.setCompressTempFiles(true);
Sheet sh = workbook.createSheet();
((SXSSFSheet) sh).setRandomAccessWindowSize(100);
//write your logic
response.setContentType("application/vnd.ms-excel");
response.setHeader("Content-Disposition", "attachment;
filename="+filename+".xlsx");
workbook.write(response.getOutputStream());
workbook.close();
workbook.dispose();

I had an out of memory issues writing a XSSFWorkbook to a file.
The Suggestions above helped a lot.
See http://poi.apache.org/components/spreadsheet/how-to.html#xssf_sax_api
Changing XSSFWorkbook wb = new XSSFWorkbook();
to SXSSFWorkbook wb = new SXSSFWorkbook(-1);
SXSSFSheet sh = ... to SXSSFSheet sh = ...
XSSFRow to SXSSFRow
XSSFCell to SXSSFCell
inside the for loop USE sh.flushRows(100); for every 100th row
after wb.write(out);
ADD wb.dispose();

Edit existing excel files using jxl api / Apache POI

I am interested and would like to learn more about java , how to write into existing excel sheets / manipulating the existing data. I was wondering if you could give me an idea on how to edit an existing excel file and save it using the jxl api / Apache POI
or perhaps give me a sample program on how to edit some data in an existing excel file and then save it
Thanks in advance !!

The tutorials here are very helpful and well-written. They use an external JAR developed by the Apache POI project.
Here's an simple example of editing one cell:
InputStream inp = new FileInputStream("wb.xls");
Workbook wb = WorkbookFactory.create(inp);
Sheet sheet = wb.getSheetAt([sheet index]);
Row row = sheet.getRow([row index]);
Cell cell = row.getCell([cell index]);
String cellContents = cell.getStringCellValue();
//Modify the cellContents here
// Write the output to a file
cell.setCellValue(cellContents);
FileOutputStream fileOut = new FileOutputStream("wb.xls");
wb.write(fileOut);
fileOut.close();
Hope it helps

One very important tip that I learned the hard way.
Open the OutputStream only after you have completed writing to your excel workbook. Zabbala's example is spot on and shows this correctly. If you open the OutputStream any earlier, your changes would not be written to the file after your program exits and you would be scratching your head as I did.

I refresh the formulas with another tab for this I use the next sentence
HSSFSheet worksheetse = workbook.getSheetAt(0);
worksheetse.setForceFormulaRecalculation(true);
but it's necesary that you apply the method setForceFormulaRecalculation for all the tabs that have the formulas.
Sorry for my English

Hello i have the same problem than neXGen. But strangely if i open the file with openoffice, it works!
Edit: perhaps i found a solution, put this after changing the values:
HSSFFormulaEvaluator.evaluateAllFormulaCells(workbook);