Runtime Error in Java code "Exception in thread "main" java.lang.NumberFormatException: For input string: "
<p>I am facing this runtime error <code>**"Exception in thread "main" java.lang.NumberFormatException: For input string: "" "**</code> please help me out to over come this. </p>

<p>Here is the code snipet :</p>

<pre><code>package SampleC;
import java.io.File;
import java.io.IOException;
import java.util. *;


import jxl.*;
import jxl.read.biff.BiffException;


import jxl.write.WriteException;

import java.util.ArrayList;
import java.util.Vector;

public class Test {
    public static void main(String args[])throws IOException, BiffException, WriteException {
    {
        try
        {
        Workbook workbook=Workbook.getWorkbook(new File("C:\\Documents and Settings\\snandam\\Desktop\\readvalues.xls"));

         Sheet sheet =workbook.getSheet(0);
    // String[] s=new String[200];
         int[] s = new int [200];
         Cell[][] cell=new Cell[100][100];

         ArrayList&lt;Integer&gt; myList = new ArrayList&lt;Integer&gt;();
         {


         for(int i=0;i&lt;sheet.getColumns();i++)
         {
             for(int j=0;j&lt;sheet.getRows(); j++)
             {
             cell[i][j] = sheet.getCell(i, j);

             s[i]=Integer.parseInt(cell[i][j].getContents());

           //  System.out.printf("%s\n", s[i]);
             Collections.addAll(myList, s[i]); 


             } 



      }


      ArrayList&lt;Integer&gt; a1 = new ArrayList&lt;Integer&gt;();
      a1.add(3);a1.add(-3);a1.add(-8);a1.add(0);

      ArrayList&lt;Integer&gt; a2 = new ArrayList&lt;Integer&gt;();
      a2.add(-1);a2.add(-4);a2.add(-7);a2.add(6);

      ArrayList&lt;Integer&gt; a3 = new ArrayList&lt;Integer&gt;();
      a3.add(1);a3.add(5);a3.add(6);a3.add(7);

      ArrayList&lt;Integer&gt; a4 = new ArrayList&lt;Integer&gt;();
      a4.add(-10);a4.add(-4);a4.add(-1);a4.add(3);a4.add(8);

      ArrayList&lt;Integer&gt; a5 = new ArrayList&lt;Integer&gt;();
      a5.add(17);a5.add(18);a5.add(19);a5.add(20);a5.add(21);a5.add(22);a5.add(23);a5.add(24);

      int target = 0;

      Vector&lt;ArrayList&lt;Integer&gt;&gt; vecOfLst   = new Vector&lt;ArrayList&lt;Integer&gt;&gt;();
      vecOfLst.add(myList);
      vecOfLst.add(a1);
      vecOfLst.add(a2);
      GlobalMembers gMem    = new GlobalMembers();
      gMem.findtarget(target, vecOfLst, 3);
      vecOfLst.add(a3);
      vecOfLst.add(a4);
      vecOfLst.add(a5);
      gMem.findtarget(target, vecOfLst, 6);
    }
} catch (BiffException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}  

        }
    }
}
</code></pre>
