Re: Can't run applet: invalid bytecode

[Jim White <jim at pagesmiths dot com>]

Kjetil Svalastog Matheussen wrote:

> On Wed, 7 Feb 2007, Kjetil Svalastog Matheussen wrote:
>
> > I can't run the scribble applet again, and I'm running cvs.
> >
> > In opera with jvm 5 I get the error "invalid bytecode",
> > In firefox with jvm 4 I get the error "Unsupported major.minor version 50.0"
> > (Do I really need hava 5? (50?))
> >
> > Appletviewer refuses totally. I'm doing the exact same things as last 
>
> No, appletviewer works. Wrong options.

That has to do with the "javac -target <version>" used to compile your 
code (actually kawa in this case).  Evidently you're using Java 6 to 
compile Kawa.

http://forum.java.sun.com/thread.jspa?threadID=5122605

If you're using the Ant build, a nice way to configure that (target 
attribute) for the <javac> task is by using ant.build.javac.target.

http://ant.apache.org/manual/CoreTasks/javac.html

target  	Generate class files for specific VM version (e.g., 1.1 or 
1.2). Note that the default value depends on the JVM that is running 
Ant. In particular, if you use JDK 1.4+ the generated classes will not 
be usable for a 1.1 Java VM unless you explicitly set this attribute to 
the value 1.1 (which is the default value for JDK 1.1 to 1.3). We highly 
recommend to always specify this attribute.
A default value for this attribute can be provided using the magic 
ant.build.javac.target property.

http://ant.apache.org/manual/javacprops.html#target

By being on such a bleeding edge, you will need to upgrade to Ant 1.7.

Alternatively you could modify the build.xml.  If you go that way, 
<PreSetDef> could be your friend (an Ant 1.6 feature that didn't exist 
when it was originally written).

http://ant.apache.org/manual/CoreTasks/presetdef.html

Jim