form:checkbox not working in Spring MVC JSP page - spring

Question

I have the following Model class:
public class BlocchettiScratchCards implements Serializable {
...
private boolean flagNuovaGestione;
public boolean isFlagNuovaGestione() {
return flagNuovaGestione;
}
public void setFlagNuovaGestione(boolean flagNuovaGestione) {
this.flagNuovaGestione = flagNuovaGestione;
}
}
and the Bean class:
public class BlocchettiScratchCardsBean implements Serializable {
...
private boolean flagNuovaGestione;
public boolean isFlagNuovaGestione() {
return flagNuovaGestione;
}
public void setFlagNuovaGestione(boolean flagNuovaGestione) {
this.flagNuovaGestione = flagNuovaGestione;
}
}
in the JSP we have a <form:form> tag with the following:
<form:checkbox path="flagNuovaGestione"/>
The controller class initialize the property as follows:
BlocchettiScratchCardsBean elencoCards = new BlocchettiScratchCardsBean();
elencoCards.setFlagNuovaGestione(true);
but when the page is loaded, the checkbox is not checked by default as I expect.
Inspecting HTML of page, I see the following:
<input id="flagNuovaGestione1" name="flagNuovaGestione" type="checkbox" value="true">
<input type="hidden" name="_flagNuovaGestione" value="on">
but the checked property is not set.
Why do I have this behaviour and how could I solve this issue?

Answer 1

I've found the solution on my own.
The problem was into the Controller class, in particular the instruction that adds the formBean into the jsp view was executed before the setting of the flagNuovaGestione boolean variable.
This was the old / not working code:
BlocchettiScratchCardsBean elencoCards = new BlocchettiScratchCardsBean();
view.addObject("formBean", elencoCards);
elencoCards.setFlagNuovaGestione(true);
and the following is the right one:
BlocchettiScratchCardsBean elencoCards = new BlocchettiScratchCardsBean();
elencoCards.setFlagNuovaGestione(true);
view.addObject("formBean", elencoCards);