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Problem in accessing c:set tag.

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Posts: 51

posted 15 years ago

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Hello all,
I am using JSP2.0. i have created one simple application in which form gets submitted and servlet gets called which creates the map and place it inside the session scope and redirect the page to the new jsp page.I am deploying the application on the server jboss 4.0.2 -GA.

Here is the Directory Structure of my Web Application.

----------------------------------
Structure of my Web Application
----------------------------------

SCWCD
|
|
WEBCONTENT
| | |
| | |
| | JSP
| | |
| | |
| | index.jsp
| WEB-INF
| | |
| | |
| | classes
| | |
| | <compiled classes>
| lib
| |
| <All the libraries are here>
finalresults.jsp

---------------------
SimpleServlet.java
---------------------
package com;
 
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
 
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import Beans.Employee;
import Beans.Person;
 
/**
 * Servlet implementation class for Servlet: SimpleServlet
 *
 */
 public class SimpleServlet extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet {
    /* (non-Java-doc)
 * @see javax.servlet.http.HttpServlet#HttpServlet()
 */
public SimpleServlet() {
super();
}

/* (non-Java-doc)
 * @see javax.servlet.http.HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
 */
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}

}         
}

-------------------------
OptionalServlet.java
-------------------------
package com;
 
import java.io.IOException;
 
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import Beans.Employee;
 
/**
 * Servlet implementation class for Servlet: OptionalServlet
 *
 */
 public class OptionalServlet extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet {
    /* (non-Java-doc)
 * @see javax.servlet.http.HttpServlet#HttpServlet()
 */
public OptionalServlet() {
super();
}

/* (non-Java-doc)
 * @see javax.servlet.http.HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
 */
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
System.out.println("do post method gets called for the optional servlet$$$");
System.out.println("\n Class of the person  attribute :" + request.getSession(false).getAttribute("person").getClass());
System.out.println("\n Value of the person  attribute :" + request.getSession(false).getAttribute("person"));
System.out.println("\n Class of the person1 attribute :" + request.getSession(false).getAttribute("person1").getClass());
System.out.println("\n Value of the person1 attribute :" + ((Employee)request.getSession(false).getAttribute("person1")).getName());
}         
}

-----------------------------------------
Output After Executing OptionalServlet
-----------------------------------------

Class of the person attribute :class java.lang.String
15:30:52,839 INFO [STDOUT]
Value of the person attribute :Beans.Employee@b1404f
15:30:52,839 INFO [STDOUT]
Class of the person1 attribute :class Beans.Employee
15:30:52,839 INFO [STDOUT]
Value of the person1 attribute :jineshparikh

Now i have read in HFSJ that when we are using the <c:set> tag then in that case either i can use the value attribute of the tag or i can specify the value in the body of the tag.What ever the evaluated value's type would be the type of the attribute.

But here in the above example look at the code of the finalresults.jsp

in the above code where i have used the body for the person1 attribute and value for the person attribute. In both of the case i have assigned them value of the attribute named person which was set in the personal attribute.Here the ${sessionScope.personal} attribute evaluates to person class object. But when i access the both of the attribute in my optionalServlet.java i got the following result

[output]
Class of the person attribute :class java.lang.String

Value of the person attribute :Beans.Employee@b1404f

Class of the person1 attribute :class Beans.Employee

Value of the person1 attribute :jineshparikh
[/output]

you can clearly see the difference in the output. For the person attribute data type is string and for the person1 attribute data type is Employee object.

My question is why there is a difference in the data type of the person and person1 attribute. when both of them are set to same value.

Please help me on this issue.

Any help would be appreciated.

Regards
Jinesh Parikh.

Please

jinesh parikh

Ranch Hand

Posts: 51

posted 15 years ago

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I found my answer on the following link

https://coderanch.com/t/291668/JSP/java/difference-between-set-body-no

Regards
Jinesh Parikh

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