JSP Bug

Question

Please c the below two bean class.
package com.bean;
public abstract class Person{
private String gf;
     public String getGf(){
          return gf;
     public void setGf(String newGf){
          this.gf = newGf;
package com.bean;
public class Employee extends Person{
private String id;
     public String getId(){
          return id;
     public void setId(String newId){
          this.id = newId;
}JSP Code:-
<jsp:useBean id="loveObj" type="com.bean.Person" class="com.bean.Employee" scope="request">
     <jsp:setProperty name="loveObj" property="gf" value="ABCD"/>
     <jsp:setProperty name="loveObj" property="id" value="14555"/>
</jsp:useBean>
GF is: <jsp:getProperty name="loveObj" property="gf" />
Employee ID is: <jsp:getProperty name="loveObj" property="id" />The output of the above code is
GF is: ABCD
Employee ID is: 14555
The prob is, as the referance type is Person and the attribute "id" is not visible for person type.
I saw the servlet code of this JSP, while setting and getting, the object is casted to Employee.
but WHY this casting is happening by default????

Answer 1

Because if the cast isn't performed the servlet wouldn't compile. Person doesn't have the setId() method, so a typecast is necessary.