GregorianCalendar为什么会是空的呢？

[SoulOfPower]

public class Employee
{
private String name;
private double salary;
private GregorianCalendar hireDay;


Employee(String name,double salary,int year,int month,int day)
{
this.name = name;
this.salary = salary;
GregorianCalendar hireDay = new GregorianCalendar(year,month-1,day);
}

public static void main(String[] args)
{
// TODO Auto-generated method stub
Employee e1 = new Employee("zhang3",1850.0,1981,12,30);
if(e1.hireDay==null)
{
System.out.println("HireDay Is Null");
}
else
{
System.out.println(e1.hireDay.get(Calendar.YEAR)+" "+(e1.hireDay.get(Calendar.MONTH)+1)
+" "+e1.hireDay.get(Calendar.DAY_OF_MONTH));
}
}
}
明明构造函数已经将hireDay初始化了～为什么还是为空～？？

[SoulOfPower]

我找到原因的～ GregorianCalendar hireDay = new GregorianCalendar(year,month-1,day); 看来我太粗心大意了～