Java, Apache POI, XSSFWorkbook extremly slow

Question

I use Apache POI to read an excel file (xlsx) This works fine in Eclipse. 30.000 rows and 20 cols are no problem. Loaded after around 5 seconds.

If I generate a runnable JAR File it doesnt process the excel file

    try {
        soeArraylist.clear();
        //JOptionPane.showMessageDialog(null, "SoE Pre Test 1", "Done" , JOptionPane.INFORMATION_MESSAGE);
        //Workbook workbook2 = new XSSFWorkbook();
        //JOptionPane.showMessageDialog(null, "SoE Pre Test 2", "Done" , JOptionPane.INFORMATION_MESSAGE); 
        
        JOptionPane.showMessageDialog(null, "SoE Import started 1", "Done" , JOptionPane.INFORMATION_MESSAGE); 
        
        FileInputStream excelFile = new FileInputStream(new File(FILE__NAME));
        JOptionPane.showMessageDialog(null, "SoE Import started 2 " + FILE__NAME, "Done" , JOptionPane.INFORMATION_MESSAGE); 
        
        
        Workbook workbook = new XSSFWorkbook(excelFile);
        JOptionPane.showMessageDialog(null, "SoE Import started 3", "Done" , JOptionPane.INFORMATION_MESSAGE); 
        
        Sheet datatypeSheet = workbook.getSheet("SoE");
        JOptionPane.showMessageDialog(null, "SoE Import started 4", "Done" , JOptionPane.INFORMATION_MESSAGE); 
        
        Iterator<Row> iterator = datatypeSheet.iterator();
        JOptionPane.showMessageDialog(null, "SoE Import started 5", "Done" , JOptionPane.INFORMATION_MESSAGE); 
        
        DataFormatter formatter = new DataFormatter(Locale.US);
        //JOptionPane.showMessageDialog(null, "SoE Import started 6", "Done" , JOptionPane.INFORMATION_MESSAGE); 
        
        JOptionPane.showMessageDialog(null, "File opened", "Done" , JOptionPane.INFORMATION_MESSAGE); 
        while (iterator.hasNext()) {

            Row currentRow = iterator.next();

 ........ code removed .......

    } catch (FileNotFoundException e) {
        e.printStackTrace();
        JOptionPane.showMessageDialog(null, "SoE Import FileNotFoundException", "FileNotFoundException" , JOptionPane.INFORMATION_MESSAGE);
    } catch (IOException e) {
        e.printStackTrace();
        JOptionPane.showMessageDialog(null, "SoE Import IOException", "IOException" , JOptionPane.INFORMATION_MESSAGE);
    }

So its stopps after SoE Import "started 2" OK it does not stopp but it looks like its processing for ages. After 1 hour still no result.

I tried to create an empty Workbook and this last 20 seconds outside from Eclipse. In Eclipse it is less than 1 second

    JOptionPane.showMessageDialog(null, "SoE Pre Test 1", "Done" , JOptionPane.INFORMATION_MESSAGE);
    Workbook workbook2 = new XSSFWorkbook();
    JOptionPane.showMessageDialog(null, "SoE Pre Test 2", "Done" , JOptionPane.INFORMATION_MESSAGE);

Java is 1.8 in Eclipse and also on the W10 machine. I know there are some similar questions here but non of them have different times between Eclipse and as standalone JAR.

Any Ideas?

Answer 1

What worked for me when I hit this issue in POI 5.0.0 was rolling back to 4.1.2, which had about a 20% performance improvement, but then also selecting "Extract required libraries into JAR" instead of "Package required libraries into JAR" which is the default Eclipse setting, which led to an about 90% improvement over rolling back to 4.1.2.