To work with my project I needed to learn about the POI Api from apache. 
So I decided to create a small program that creates a spreadsheet and fills its cells with some values .   

The problem is it doesn't do what it was supposed to and I'm pretty sure the logic is correct, I doubt this has something to do with the way data are written to files but I can't fix it as I have a very poor experience dealing with I/O.   

This is my code :

```
package excel;
import java.io.FileOutputStream;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;

public class Excel {

    public static void main(String[] args) {

        Workbook workbook = new HSSFWorkbook();
         Sheet sheetTest = workbook.createSheet("TestPOI");

         Cell[] cell = new Cell[100];
         int k = 0, i=0, j=0;

         for( i=0; i<10; i++){
             for (j = 0; j < 10; j++) {
                 System.out.println(k);
                 cell[k] = sheetTest.createRow(i).createCell(j);
                 cell[k].setCellValue(k);
                 k++;
             }
         }

    try{
    FileOutputStream output = new FileOutputStream("MyWorkbook.xls");
    workbook.write(output);
    output.close();
    } //end try
    catch(Exception e){
    e.printStackTrace();
    } //end catch

    } // end of the main method
}

```

Thanks in advance
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