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Passing custom objects from servlet to JSP

Tags:

jsp

session

I want to pass a custom object of type Student from a servlet to JSP. I have created a Student bean class. Student contains 2 properties firstname and lastName.

Student bean:

import java.io.Serializable;

public class Student implements Serializable {

    public Student() {
    }

    String firstName;
    String lastName;

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

}

HTML file for taking FirstName and LastName from the user:

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
</head>
<body>
    <form id="myForm" method="POST" action="MyFormServlet">
        FirstName<input type="text" id="firstName"  name="FirstName"/><br>
        LastName<input type="text" id="lastName" name="LastName"/><br>
        <button type="submit" />Submit</button>
    </form>
</body>
</html>

Servlet Code:

import javax.servlet.RequestDispatcher;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;



    public class MyFormServlet extends HttpServlet {

        @Override
        protected void doPost(HttpServletRequest request,
                HttpServletResponse response) {

            Student s = new Student();
            s.setFirstName(request.getParameter("FirstName"));
            s.setLastName(request.getParameter("LastName"));

            HttpSession session =request.getSession();
            session.setAttribute("student", s);

            try {
                RequestDispatcher rd = getServletContext().getRequestDispatcher("/myJsp.jsp");
                rd.forward(request, response);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

    }

myJsp.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
</head>
    <body>
        <%
            // I want to do something like this :   
            //Student student =(Student)session.getAttribute("student");
            //String fullName=student.firstName + student.lastName;
        %>      
        <h1><%=fullName%></h1>
    </body>
</html>

I want to get the 'student' object, access its attributes and store it in a JSP variable for further processing.

like image 792
Ash Ash Avatar asked Apr 24 '12 10:04

Ash Ash


2 Answers

The setAttribute() method on request, session and servletContext will already make it available as a JSP/EL variable by the attribute name.

In your particular case, with the following line in the servlet,

session.setAttribute("student", s);

it's available in JSP/EL as ${student}. So, just this should do:

<body>
    <h1>${student.firstName} ${student.lastName}</h1>
</body>

If you want to store it as another variable in JSP so that you can reuse it multiple times, use JSTL <c:set>.

<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
...
<body>
    <c:set var="fullName" value="${student.firstName} ${student.lastName}" />
    <h1>${fullName}</h1>
</body>
like image 189
BalusC Avatar answered Nov 15 '22 10:11

BalusC


You should pass attributes to request scope if not required to use throughout session. In Servlet,

 request.setAttribute("student", s);

In JSP,

Student student =(Student) request.getAttribute("student");
String fullName = "Default";
if(student!=null){
 fullName=student.firstName +" " + student.lastName;
}
like image 24
Hardik Mishra Avatar answered Nov 15 '22 09:11

Hardik Mishra