从对象流中读取对象，请在下面横线处填写代码完成此程序。
import java.util. *;
import java. io. *;
public class UnSerializeDate
{
date d = null;
UnSerializeDate ( )
{
try
{
FileInputStream f1 = new FileInputStream("date.ser");
d = (Date) s. readobject ();
f1,close();
}
catch (Exceptin e)
{
e. printStackTrace ();
}
}
public static main(String args [] )
{
System.out.println("The date read is: "+ a.d.toString());
}
}