Need Help with Grid cells

Based on your other post in this forum I'm going to guess you're planning on using Vaadin 8.

(I'm writing this code on the directly here, so there might be some syntax errors) (also I'm new to Vaadin 8 so there might be better/cleaner ways of doing this)

// the bean in the grid
public class GridRow {
  private int hours; // 0 - 23
  // other data

  public int getHours() { return hours; }

  public void setHours(int hours) { this.hours = hours; }
}

// in the view/UI
...
  Grid<GridRow> grid = new Grid<>(GridRow.class);
  
  Binder<GridRow> binder = grid.getEditor().getBinder();
  TextField hoursField = new TextField();
  // in Vaadin 7 you'd add the Converter/Validator directly to the TextField
  Binder.Binding<GridRow, Integer> hoursBinding = binder.forField(hoursField)
      .withConverter(new StringToIntegerConverter)
      .withValidator(new IntegerRangeValidator("Value must be between 0 and 23", 0, 23))
      .bind(Person::getHours, Person::setHours);
  // in Vaadin 7 you'd do grid.addColumn("hours").setEditorField(hoursField)
  grid.addColumn("hours").setEditorBinding(hoursBinding);

  // enable grid editing, define listeners for editing events
...
  

Hope that helps