Apache POI reads wrong date format of Excel sheet by the XSSF reader

Question

I want to read specific value of cell in Excel sheet.Currently my code is giving General value instead of Custom value of cell.
For cite an Example :- Now,

• I am giving the input in Excel sheet Custom(Cell type)--> 01/10/2250.
• output is converting in General value of Cell--->128110 (The cell is in format 'General', this is an important point becuse it is this specific condition that causes the error we have).

We are using XSSF reader and XMLReader and now Workbook because of memory issues with workbook. (we see alot of answers on the we for workbook not for XSSF)

Test cases

• input --> 01/10/2250
• Desired output -->01/10/2250
• Actual output---->128110

---

• input --> 12-25-2250
• Desired output -->12-25-2250
• Actual output---->128110

---

• input --> 2250-25-12
• Desired output -->2250-25-12
• Actual output---->128195

Please mind all the input pattern with the hyphen(-) and slash(/).

strong text This is code---->

import java.io.InputStream;
import java.util.Iterator;
import org.apache.poi.openxml4j.opc.OPCPackage;
import org.apache.poi.xssf.eventusermodel.XSSFReader;
import org.apache.poi.xssf.model.SharedStringsTable;
import org.apache.poi.xssf.usermodel.XSSFRichTextString;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.helpers.XMLReaderFactory;
public class  DateCellDemo {
    public void processOneSheet(String filename) throws Exception {
        OPCPackage pkg = OPCPackage.open(filename);
        XSSFReader r = new XSSFReader( pkg );
        SharedStringsTable sst = r.getSharedStringsTable();

        XMLReader parser = fetchSheetParser(sst);

        InputStream sheet2 = r.getSheet("rId1");
        InputSource sheetSource = new InputSource(sheet2);
        parser.parse(sheetSource);
        sheet2.close();
    }

    public void processAllSheets(String filename) throws Exception {
        OPCPackage pkg = OPCPackage.open(filename);
        XSSFReader r = new XSSFReader( pkg );
        SharedStringsTable sst = r.getSharedStringsTable();

        XMLReader parser = fetchSheetParser(sst);

        Iterator<InputStream> sheets = r.getSheetsData();
        while(sheets.hasNext()) {
            System.out.println("Processing new sheet:\n");
            InputStream sheet = sheets.next();
            InputSource sheetSource = new InputSource(sheet);
            parser.parse(sheetSource);
            sheet.close();
            System.out.println("");
        }
    }

    public XMLReader fetchSheetParser(SharedStringsTable sst) throws SAXException {
        XMLReader parser =
            XMLReaderFactory.createXMLReader(
                    "org.apache.xerces.parsers.SAXParser"
            );
        ContentHandler handler = new SheetHandler(sst);
        parser.setContentHandler(handler);
        return parser;
    }

    private static class SheetHandler extends DefaultHandler {
        private SharedStringsTable sst;
        private String lastContents;
        private boolean nextIsString;

        private SheetHandler(SharedStringsTable sst) {
            this.sst = sst;
        }

        public void startElement(String uri, String localName, String name,
                Attributes attributes) throws SAXException {
            // c => cell
            if(name.equals("c")) {
                // Print the cell reference
                System.out.print(attributes.getValue("r") + " - ");
                // Figure out if the value is an index in the SST
                String cellType = attributes.getValue("t");
                //System.out.println("------ cellType :"+cellType);
                if(cellType != null && cellType.equals("s")) {
                    nextIsString = true;
                } else {
                    nextIsString = false;
                }
            }
            // Clear contents cache
            lastContents = "";
        }

        public void endElement(String uri, String localName, String name)
                throws SAXException {
            // Process the last contents as required.
            // Do now, as characters() may be called more than once
            if(nextIsString) {
                System.out.println("Date Pattren : "+nextIsString);
                int idx = Integer.parseInt(lastContents);
                lastContents = new XSSFRichTextString(sst.getEntryAt(idx)).toString();
            }

            // v => contents of a cell
            // Output after we've seen the string contents
            if(name.equals("v")) {
                System.out.println("Last_Content : "+lastContents);
            }
        }

        public void characters(char[] ch, int start, int length)
                throws SAXException {
            lastContents += new String(ch, start, length);
        }
    }

    public static void main(String[] args)  {
        try {
            DateCellDemo howto = new DateCellDemo();
            howto.processOneSheet("C:\\Users\\Dell\\Downloads\\Source11_Data.xlsx");
        } catch (Exception e) {
            e.printStackTrace();
        }


    }
}

Answer 1

There is another Apache POI example (XLSX2CSV) that lets you stream the input xlsx but get access to formatted cell data. Your code is based on another sample which reads the raw XML from the xlsx file (and the raw XML has the dates in numeric format).

This is based on that sample: https://github.com/pjfanning/poi-shared-strings-sample/blob/master/src/main/java/com/github/pjfanning/poi/sample/XLSX2CSV.java