CODEWITHSUNDEEP
javajsp
Drunken Daddy
Drunken Daddy

Reputation: 8001

sendRedirect() not working as expected

I've this Register.jsp page which on page load, I want to check if a user is already logged in. So I've this code,

<%
    String usertype = (String)session.getAttribute("usertype");
    if(usertype.equals("student")){
        response.sendRedirect("studenthome.jsp");
    }
    else if(usertype.equals("faculty")){
        response.sendRedirect("facultyhome.jsp");
    }       
%>

It works when a user is logged in(it redirects to studenthome.jsp if usertype equals student and redirects to facultyhome.jsp if usertype equals faculty), but when usertype is null, I just want to continue loading the page instead I get following error. What am I doing wrong here

Upvotes: 2

Views: 90

Answers (2)

Braj
Braj

Reputation: 46881

Try to avoid Scriplet at all in 21st century instead use JavaServer Pages Standard Tag Library

Try with c:redirect and c:choose. Find more details about Oracle Tutorial - Core Tag Library

There is no need to handle NullPointerException using JSTL (in this case) as shown in below sample code.

Sample code: 

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

<c:choose>
    <c:when test="${usertype == 'student'}">
        <c:redirect url="studenthome.jsp" />
    </c:when>
    <c:when test="${usertype == 'faculty'}">
        <c:redirect url="facultyhome.jsp" />
    </c:when>
    <c:otherwise>
        <c:redirect url="home.jsp" />
    </c:otherwise>
</c:choose>

Note: remove c:otherwise if not needed.

Upvotes: 1

Masudul
Masudul

Reputation: 21981

When usertype is null, I just want to continue loading the page instead of getting error.

You will get NullPointerException if usertype is null. You can simply ignore this error by swap the position of usertype on equals method of if-else condition

if("student".equals(usertype)){
    response.sendRedirect("studenthome.jsp");
}
else if("faculty".equals(usertype)){
    response.sendRedirect("facultyhome.jsp");
}

Upvotes: 2

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