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Exception in thread "main"

ShivKumar Rajawat

Joined: Mar 13, 2007
Posts: 17
Hi everybody
I am trying to run a small program on a new "Windows XP" system. i am using jdk 1.5.0. it's the same old "hello world" program. it compiles without any errors or warnings , but when i try to run this program it displays this exception :

Exception in thread "main" java.lang.UnsupportedClassVersionError: hi (Unsupport
ed major.minor version 49.0)
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at Source)
at Source)
at$100(Unknown Source)
at$ Source)
at Method)
at Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)

the class code is :

public class hi
public static void main (String [] args)

can somebody please explain what may be causing this exception

Regards<br />-Shiv
Paul Sturrock

Joined: Apr 14, 2004
Posts: 10336

Looks like you are compiling your code with JDK 1.5.0 but trying to run it with a 1.4 JRE. If you have both installed make sure you are using the version of Java you thing you are (try java -version fro mthe command line).

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Urs Waefler
Ranch Hand

Joined: Mar 13, 2007
Posts: 77

Always when I see such messages, I have a look at the Java API. There is a Class UnsupportedClassVersionError. Me too, I do not understand at the moment. I only know it is an Error.

Further one can read in the API: Thrown when the Java Virtual Machine attempts to read a class file and determines that the major and minor version numbers in the file are not supported.

Best Regards

SCJP 1.4
ShivKumar Rajawat

Joined: Mar 13, 2007
Posts: 17
Thanks Paul and Urs,
I checked the version of java. this is ""

D:\>java -version
java version ""
Java(TM) 2 Runtime Environment, Standard Edition (build
Java HotSpot(TM) Client VM (build 1.3.1-rc2-b22, mixed mode)

then recomplied the class with
D:\>javac -source 1.3 shiv/

even then the same error persists.

who told me to be a software engineer!!
Jesper de Jong
Java Cowboy
Saloon Keeper

Joined: Aug 16, 2005
Posts: 14998

Why do you have Java 1.3.1 on your system? Uninstall that old version.

Do you have Oracle software on your system? Oracle has the bad habit of supplying a Java 1.3 JRE with their software.

Check your PATH setting and make sure that your Java 5 JRE is in the PATH correctly. Remove the Java 1.3 JRE from the PATH.

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ShivKumar Rajawat

Joined: Mar 13, 2007
Posts: 17
Thanks Jesper,
you are right. i have Oracle Jinitiater in my system that is causing this problem.

thanks a lot guys ..
I agree. Here's the link:
subject: Exception in thread "main"
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