Java, JMesa checkbox

I want to create a JMesa checkbox by Java.

I have the following code

HtmlColumn activo =  new HtmlColumn("activo");
 activo.setCellEditor(new CheckboxWorksheetEditor());
 htmlRow.addColumn(activo)

;

This code return a null when I render the table in jsp.

How do I have to create a checkbox with Java and JMesa?