java.lang.NumberFormatException: For input string

Hi,
I am get the following error when trying to dynamically load an htmldatatable:

View code:

Backing bean code:

private HtmlDataTable lbrrtdt;
  private HibernateDAO hdao = new HibernateDAO ();
  private HtmlPanelGrid gridPanel1;
	
	public void setGridPanel1(HtmlPanelGrid gridPanel1) {
		this.gridPanel1 = gridPanel1;
	}
	
	public HtmlPanelGrid getGridPanel1() {			
      return gridPanel1;
  }
  
  public void findComp()
    {	  
  
	String qry = "select colA,colB from table";
	ArrayList repData= (ArrayList)hdao.hibQryRes(qry);
	FacesContext facesContext = FacesContext.getCurrentInstance();
	ELContext elContext = facesContext.getELContext();
	Application application = facesContext.getApplication();
	ExpressionFactory elFactory = facesContext.getApplication().getExpressionFactory();
      UIColumn col = null;         
      UIOutput txt = null;
      this.lbrrtdt = new HtmlDataTable();
      this.lbrrtdt.setVar("rep");
      lbrrtdt.setValue(repData); 
      
    
      col = new UIColumn();
  
      UIOutput header = new UIOutput();      
      header.setValue("header1");
     
      col.setHeader(header);      
          
      txt = new UIOutput();      
      ValueExpression valueExpression = elFactory.createValueExpression( elContext, "#{rep.colA}", String.class);

txt.setValueExpression("value", valueExpression);

col.getChildren().add(txt);
      this.lbrrtdt.getChildren().add(col);
     this.gridPanel1.getChildren().add(this.lbrrtdt);              
    }
  
 
	 public void setLbrrtdt(HtmlDataTable lbrrtdt) {
	        this.lbrrtdt = lbrrtdt;
	    }

public HtmlDataTable getLbrrtdt() {
	        return lbrrtdt;
	    }

Data access layer is hibernate.
Hibernate entity code for colA:

Any input appreciated.

Thanks.