JAVA use apache poi creates xlsx, all the rows after 9th will be inserted back to 2nd row

Question

I'm following the Apache POI – Spreadsheets tutorial from this site: https://www.tutorialspoint.com/apache_poi/apache_poi_spreadsheets.htm

Everything works fine, but when I try to add more than 10 rows, all rows after 9th will be inserted back from the 2nd row. I am new in JAVA, is there anything wrong with the loop to iterate the data or something else? Please help!

I used the entire code from the tutorial but added some more lines to create more rows:

package testing;

import java.io.File;
import java.io.FileOutputStream;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class Testing {

    /**
     * @param args the command line arguments
     * @throws java.lang.Exception
     */



   public static void main(String[] args) throws Exception 
   {
      //Create blank workbook
      XSSFWorkbook workbook = new XSSFWorkbook(); 
      //Create a blank sheet
      XSSFSheet spreadsheet = workbook.createSheet( 
      " Employee Info ");
      //Create row object
      XSSFRow row;
      //This data needs to be written (Object[])
      Map < String, Object[] > empinfo = 
      new TreeMap < String, Object[] >();
      empinfo.put( "1", new Object[] { 
      "EMP ID", "EMP NAME", "DESIGNATION" });
      empinfo.put( "2", new Object[] { 
      "tp01", "Gopal", "Technical Manager" });
      empinfo.put( "3", new Object[] { 
      "tp02", "Manisha", "Proof Reader" });
      empinfo.put( "4", new Object[] { 
      "tp03", "Masthan", "Technical Writer" });
      empinfo.put( "5", new Object[] { 
      "tp04", "Satish", "Technical Writer" });
      empinfo.put( "6", new Object[] { 
      "tp05", "Krishna", "Technical Writer" });
      empinfo.put( "7", new Object[] { 
      "tp06", "Krishna", "Technical Writer" });
      empinfo.put( "8", new Object[] { 
      "tp07", "Krishna", "Technical Writer" });
      empinfo.put( "9", new Object[] { 
      "tp08", "Krishna", "Technical Writer" });
      empinfo.put( "10", new Object[] { 
      "tp09", "Krishna", "Technical Writer" });
      empinfo.put( "11", new Object[] { 
      "tp10", "Krishna", "Technical Writer" });

      //Iterate over data and write to sheet
      Set < String > keyid = empinfo.keySet();
      int rowid = 0;
      for (String key : keyid)
      {
         row = spreadsheet.createRow(rowid++);
         Object [] objectArr = empinfo.get(key);
         int cellid = 0;
         for (Object obj : objectArr)
         {
            Cell cell = row.createCell(cellid++);
            cell.setCellValue((String)obj);
         }
      }
      //Write the workbook in file system
      FileOutputStream out = new FileOutputStream( 
      new File("Writesheet.xlsx"));
      workbook.write(out);
      out.close();
      System.out.println( 
      "Writesheet.xlsx written successfully" );
   }
}

If I run the code, the generated *.xlsx file will be: example.xlsx

Anyway to make it works normally?

Gyunesh Shefkedov Gyunesh Shefkedov · Accepted Answer · 2017-04-12T20:14:43

Treemap sorts the keys that's why the final result is different than expected. Try using linkedhashmap which saves the insertion order.

JAVA use apache poi creates xlsx, all the rows after 9th will be inserted back to 2nd row

1 Answers