Spring MVC: Set Year field using Joda DateTime

GOAL:

Set 4-digit Year (e.g. 1999) field to LocalDate Controller attribute. How do I set the input::1999 to DateTime object in Spring MVC?

JSP:

<form:form action="${url}" method="POST" commandName="form">
    <form:input id="year" path="works[0].startDate.year"/>
</form:form>

SETTER: DateTime updated with 4-digit year

@XmlRootElement
@XmlAccessorType(XmlAccessType.FIELD)
public class WorkRequest {
    @DateTimeFormat(pattern = "MM/dd/yyyy")
    @XmlElement(name = "start_date")
    public DateTime startDate;

    public void setStartDate(DateTime startDate){
    //update 4-digit only
    }    
}