java.lang.NoCla ssDefFoundError

[Lem]

I get the error
Exception in thread "main" java.lang.NoCla ssDefFoundError

when I type java app2 in the command prompt. I've tried moving to the jre
directory and typed java c:\app2\app2, but it gives me the same exception.
What could be the problem?

Thanks in advance,
Lem

[Lem]

There is nothing wrong with the code, it compiles fine, moreover the sdk
examples do not work as well.

Lem

[Mel Roman]

In article <bg**********@n obel.pacific.ne t.sg>, Lem wrote:

There is nothing wrong with the code, it compiles fine, moreover the sdk
examples do not work as well.

If the SDK examples also don't work, then that seems to point back to a
CLASSPATH problem. To verify that this is the issue, you can try
invoking java using the cp switch to tell it explicitly where to find the class.
For example, if your app2.class is in a directory called c:\mydir, then
you could try

java -cp c:\mydir app2

(assuming the cp switch works the same in the Windows implementation -
I'm working from a linux box). If that works, then we at least know
that it's a classpath problem.

Mel Roman
me*@melroman.ne t

[Lem]

Thanks, the -cp switch worked, one thing I don't understand though, I ran my
app from its directory, shouldn't the jre start searching there first?

Thanks in advacnce,
Lem
"Mel Roman" <me*@melroman.n et> wrote in message
news:IO******** ***********@new s04.bloor.is.ne t.cable.rogers. com...

In article <bg**********@n obel.pacific.ne t.sg>, Lem wrote:

There is nothing wrong with the code, it compiles fine, moreover the sdk
examples do not work as well.

If the SDK examples also don't work, then that seems to point back to a
CLASSPATH problem. To verify that this is the issue, you can try
invoking java using the cp switch to tell it explicitly where to find the

class. For example, if your app2.class is in a directory called c:\mydir, then
you could try

java -cp c:\mydir app2

(assuming the cp switch works the same in the Windows implementation -
I'm working from a linux box). If that works, then we at least know
that it's a classpath problem.

Mel Roman
me*@melroman.ne t

[Mel Roman]

In article <bg**********@n obel.pacific.ne t.sg>, Lem wrote:

Thanks, the -cp switch worked, one thing I don't understand though, I ran my
app from its directory, shouldn't the jre start searching there first?
--

At least this confirms that it's a classpath problem. As you say,
java should search the current directory (as well as those directories
specified in your CLASSPATH environment variable) to find your
app2.class file. Specifically, if your app2.class file is in your
c:\mydir directory, then you should be able to run app2 like this:

cd c:\mydir
java app2

You've already confirmed that you've tried this without success. I
can't explain why that isn't working for you. Perhaps one of our more
experienced brethren can offer an explanation.

At any rate, another poster recommended that you check and (if
necessary) modify your CLASSPATH. You'll probably want to define a file
hierarchy for storing all of your compiled *.class files (organized by
package) and put the top-level directory of that hierarchy in your CLASSPATH.
This link in the Sun tutorial talks about this:

http://java.sun.com/docs/books/tutor...gingfiles.html

Good luck,
Mel Roman
me*@melroman.ne t

[Chris]

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Hash: SHA1

Mel Roman wrote:

<snip>

cd c:\mydir
java app2

You've already confirmed that you've tried this without success. I
can't explain why that isn't working for you. Perhaps one of our
more experienced brethren can offer an explanation.

<snip>

Hi,
I have a pretty good idea of what the problem MIGHT be. The virtual
machine doesn't search in the current directory for class files,
unless the CLASSPATH variable is not set, or tells it to. That is, if
you must set CLASSPATH, set it so that the first item is . like this:

If your CLASSPATH needs to include "c:\mylib.j ar" for some reason, and
it is set like so:

SET CLASSPATH=c:\my lib.jar

replace it with this:

SET CLASSPATH=.;c:\ mylib.jar

On the other hand, if you don't need CLASSPATH, get rid of it and
everything should also be fine.

- --
Chris
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[Mel Roman]

In article <Rw************ ********@news1. telusplanet.net >, Chris wrote:

I have a pretty good idea of what the problem MIGHT be. The virtual
machine doesn't search in the current directory for class files,
unless the CLASSPATH variable is not set, or tells it to. That is, if
you must set CLASSPATH, set it so that the first item is . like this:

Thanks for the input, Chris. I was playing with this a little while ago
myself. I didn't initially have any CLASSPATH variable, and executing
java myapp from within myapp's current directory worked just fine. Even
after setting my CLASSPATH to /home/mel/java, I can still always execute
an app from the current directory (outside of the CLASSPATH). Your
comments make me wonder if different java implementations behave differently.

Lem: Try doing what Chris says and see if that allows you to execute
"normally" (without the -cp switch) from the current directory. I'd be
interested in hearing your answer.

-

Mel Roman
me*@melroman.ne t

[Lem]

Thanks, it works =)

Lem
"Mel Roman" <me*@melroman.n et> wrote in message
news:98******** ***********@new s04.bloor.is.ne t.cable.rogers. com...

In article <Rw************ ********@news1. telusplanet.net >, Chris wrote:

I have a pretty good idea of what the problem MIGHT be. The virtual
machine doesn't search in the current directory for class files,
unless the CLASSPATH variable is not set, or tells it to. That is, if
you must set CLASSPATH, set it so that the first item is . like this:
Thanks for the input, Chris. I was playing with this a little while ago
myself. I didn't initially have any CLASSPATH variable, and executing
java myapp from within myapp's current directory worked just fine. Even
after setting my CLASSPATH to /home/mel/java, I can still always execute
an app from the current directory (outside of the CLASSPATH). Your
comments make me wonder if different java implementations behave

differently.
Lem: Try doing what Chris says and see if that allows you to execute
"normally" (without the -cp switch) from the current directory. I'd be
interested in hearing your answer.

-

Mel Roman
me*@melroman.ne t

[George Neuner]

On Sun, 27 Jul 2003 20:40:06 +0800, "Lem" <hj***@pacific. net.sg>
wrote:

I get the error
Exception in thread "main" java.lang.NoCla ssDefFoundError

when I type java app2 in the command prompt. I've tried moving to the jre
directory and typed java c:\app2\app2, but it gives me the same exception.
What could be the problem?

Thanks in advance,
Lem

You didn't say what environment, but your example above uses
DOS/Windows directory syntax. Sun's Java CL (if that's what you are
using) has Unix CL semantics ... try prefixing ".\" (current
directory) to the name of the class file you want to run, eg., "java
..\app2".

If that doesn't work, try using forward slashes "/" in the filespec.
There is (or use to be) an environment setting for the JRE that tells
it which to expect ... sorry, I don't remember what the setting is/was
- I only had to use it once long ago.

George

[Mel Roman]

In article <3f************ ***********@new s.dial.pipex.co m>, Peter Bradley wrote:

Hi guys and gals,

I've never understood $CLASSPATH and packages and friends - but I had the
same problem, which is why I'm reading this thread.

I can't be sure, but I suspect that this Chris' comments may apply here
again. What is the value of your CLASSPATH variable? As Chris said,
clearing it may force java to look in your current directory.
--

Mel Roman
me*@melroman.ne t