Why I cannot Create an Object of Some JAVA class in JSP page

Question

I have following JAVA class named as Demo of com package

package com;
public class Demo 
{
public String getMessage()
{
    return "hello";
}
}

now i want to call a method of Demo class in my index.jsp page

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

<!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">
<title>Service Call Management</title>
</head>
<body>
<h1>
<% 
Demo d = new Demo();
out.println(d.getMessage());    
%> 
</h1>
</body>
</html>

but i get this error by my Apache 7.0.35 server in Eclipse Kepler

type Exception report

message An exception occurred processing JSP page /index.jsp at line 13

description The server encountered an internal error that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: An exception occurred processing JSP page /index.jsp  at line 13

10: <body>
11: <h1>
12: <% 
13:     Demo d = new Demo();
14:     out.println(d.getMessage());    
15: %>
16: </h1>

so please help me to resolve this issue

Here is the Stack Trace

Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:568)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:455)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

here is the root cause

root cause

javax.servlet.ServletException: java.lang.UnsupportedClassVersionError: com/Demo :   Unsupported major.minor version 51.0 (unable to load class com.Demo)
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java :912)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:841)
org.apache.jsp.index_jsp._jspService(index_jsp.java:90)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

root cause

java.lang.UnsupportedClassVersionError: com/Demo : Unsupported major.minor version 51.0 (unable to load class com.Demo)
org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2908)
org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1173)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1681)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:126)
org.apache.jasper.servlet.JasperLoader.loadClass(JasperLoader.java:63)
java.lang.ClassLoader.loadClassInternal(Unknown Source)
org.apache.jsp.index_jsp._jspService(index_jsp.java:76)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

Stacktrace: org.apache.jasper.servlet.JspServletWrapper.handleJspExcepti on(JspServletWrapper.java:568) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:455) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334) javax.servlet.http.HttpServlet.service(HttpServlet.java:728) — Vimesh Shah, Dec 24 '13 at 14:23

Jorge_B · Accepted Answer · 2014-03-15T00:17:55.870

1

Your code looks right at first sight. The logical explanation would be that you have not packaged your Demo.class in the right place in the web application. Your .war (or exploded directory) should look like this:

application.war/
               index.jsp
               /WEB-INF/web.xml
               /WEB-INF/classes/com/Demo.class
... additional stuff

That's the minimum necessary configuration, have a look at it and look if there is something missing

Edited to add the real answer after exchanging some ideas with the OP:

Actually the problem was that the code was compiled with a more recent version of the java compiler than the runtime environment used in the server, thus the java.lang.UnsupportedClassVersionError reported by the OP.

edited Mar 15 '14 at 00:17

answered Dec 24 '13 at 14:49

Jorge_B

9,712
2
17
22

Directory structure of my Application is Correct but I still getting same error .. – Vimesh Shah Dec 24 '13 at 14:57
Do you have any further information on the exception trace? It should have a cause – Jorge_B Dec 24 '13 at 15:03
Jorge_B i added a root cause in the question – Vimesh Shah Dec 24 '13 at 15:22
2

Then it looks like you have compiled your code against a java version upper than the runtime you use in your application server. You will fix that by recompiling aiming to a lower java version (the one you are using in your server) – Jorge_B Dec 24 '13 at 15:33
1

Was the real answer here about the compilation version? Care to edit your answer to add that in as opposed to leaving it in the comments? – Gray Mar 14 '14 at 21:13

score 1 · Answer 2 · edited May 23 '17 at 10:24

1

Do not write scriptlets in JSP, because scriptlets shouldn't be used in JSPs for more than a decade. Learn the JSP EL, the JSTL, and use servlet for the Java code.
See How to avoid Java Code in JSP-Files?

Solution

You can use Java bean, best explained here is link
Modify the class as per Java bean standard

package com;
public class Demo 
{
  private String message;
  public String getMessage()
  {
     return message;
  }

  public void setMessage(String message)
  {
     this.message = message;
  }
}

JSP

<jsp:useBean id="demo" class="com.Demo" scope="page">
   <jsp:setProperty name="demo" property="message" value="hello" />
</jsp:useBean>

//to retrieve value
<jsp:getProperty name="demo" property="message"/>

edited May 23 '17 at 10:24

Community

1
1

answered Dec 24 '13 at 14:50

Aniket Kulkarni

12,825
9
67
90

Demo is not JavaBean i just want to simple java class – Vimesh Shah Dec 24 '13 at 14:58
@VimeshShah : Ok, but use of scriptlets `<% %>` in JSP is not recommended at all. – Aniket Kulkarni Dec 26 '13 at 04:37

Why I cannot Create an Object of Some JAVA class in JSP page

2 Answers2

Solution

JSP

Linked