Hi,

I have downloaded a 3:rd party jar file. When I try to run my code ( 
using the API) I get the following error:

class file has wrong version 49.0, should be 48.0

AFAIK: The class file i generated using jdk 1.5 and I try to execute it 
using jdk 1.4.

I cannot change jdk but use 1.4 ( sniff).

The provider of the jar file has the following requirements:

Requirements
Java2HTML is written in Java and therefore needs a Java 1.1 or above 
compatible JVM

Is there a way around this?

cheers,

//mikael

"Petterson Mikael" <mikael@no.reply.to.se> wrote:

> AFAIK: The class file i generated using jdk 1.5 and I try
> to execute it using jdk 1.4.

When you write "generated", I assume you mean "compiled"...

> I cannot change jdk but use 1.4 ( sniff).

I assume you mean that you run it on another machine, having only jre 1.4.

From what I can guess of your post, you have two main options, of which you 
could try the first one first:

1. Compile with jdk 1.5, but use the switch "-target 1.4"

http://java.sun.com/j2se/1.5.0/docs/tooldocs/windows/javac.html

Also look at the cross-compilation example at the bottom of that page.

If that still doesn't work...

2. Download the 1.4 jdk to your development machine as well, and
   use that when compiling this code.

Most IDE's for Java have the possibility to switch between different jdk:s, 
so there's no need to remove 1.5.

/// Bjorn A

On Wed, 27 Jun 2007 09:47:22 +0200, Petterson Mikael
<mikael@no.reply.to.se> wrote, quoted or indirectly quoted someone who
said :

>I have downloaded a 3:rd party jar file. When I try to run my code ( 
>using the API) I get the following error:
>
>class file has wrong version 49.0, should be 48.0
>
>AFAIK: The class file i generated using jdk 1.5 and I try to execute it 
>using jdk 1.4.
>
>I cannot change jdk but use 1.4 ( sniff).
>
>The provider of the jar file has the following requirements:
>
>Requirements
>Java2HTML is written in Java and therefore needs a Java 1.1 or above 
>compatible JVM
>
>Is there a way around this?

He has presumably used JDK 1.5 features and methods not available in
JDK 1.4.  What can you do?

1. upgrade to JDK 1.6.
see http://mindprod.com/jgloss/jdk.html
JDK 1.4 came out 2002-02-13. That is 5 years ago an extremely long
time in net years. That was even before the Iraq war started.

2. decompile the code, and modify it to avoid JDK 1.5 features.  If
you are lucky there won't be any.  Any Genericity disappears on
decompilation. see http://mindprod.com/jgloss/decompiler.html


--
Roedy Green Canadian Mind Products
The Java Glossary
http://mindprod.com