Help with "main" error

Re: Help with "main&quot ; error

news wrote:[color=blue]
>
> I am pretty new to Java and I just install the JDK1.4.2 03
> I am getting an error when I run the class file TestChart.class with the
> java.exe:[/color]

What's your command line? What is the full error message? We can't
read your mind, or your screen; and withholding important information
like that makes it very difficult to answer your question.

--

The Easiest Way to Train Anyone... Anywhere.

Chris Smith - Lead Software Developer/Technical Trainer
MindIQ Corporation

Re: Help with "main&quot ; error

I use the command line as follows:

c:\j2sdk1.4.2_0 3\bin\java d:\personal\jav a-ChartGen\TestCh art.class

The full error message is as follows:

Exception in thread "main" java.lang.NoCla ssDefFoundError :
d:\personal\jav a-ChartGen\TestCh art/class


I thought it may be the CLASSPATH, but all my class files are located in the
same folder and I used the switch -classpath but the same error comes up.



"Chris Smith" <[email protected] t> wrote in message
news:MPG.1a4566 9187e98ca498980 [email protected] ...[color=blue]
> news wrote:[color=green]
> >
> > I am pretty new to Java and I just install the JDK1.4.2 03
> > I am getting an error when I run the class file TestChart.class with the
> > java.exe:[/color]
>
> What's your command line? What is the full error message? We can't
> read your mind, or your screen; and withholding important information
> like that makes it very difficult to answer your question.
>
> --
> www.designacourse.com
> The Easiest Way to Train Anyone... Anywhere.
>
> Chris Smith - Lead Software Developer/Technical Trainer
> MindIQ Corporation[/color]

Re: Help with &quot;main&quot ; error


"news" <[email protected]> wrote in message
news:uFRCb.1839 $D66.1494@nwrdn y03.gnilink.net ...[color=blue]
> I use the command line as follows:
>
> c:\j2sdk1.4.2_0 3\bin\java d:\personal\jav a-ChartGen\TestCh art.class
>
> The full error message is as follows:
>
> Exception in thread "main" java.lang.NoCla ssDefFoundError :
> d:\personal\jav a-ChartGen\TestCh art/class
>
> I thought it may be the CLASSPATH, but all my class files
> are located in the same folder and I used the switch -classpath
> but the same error comes up.
>[/color]

You shouldn't be using the '.class' extension on the command-line. The JVM
expects a classname, so you would be better off doing:

c:\j2sdk1.4.2_0 3\bin\java d:\personal\jav a-ChartGen\TestCh art

Alternatively:

* Set your PATH [similar to setting the CLASSPATH as
I earlier described] to include the location of the J2SDK
binaries

set PATH=%path%;c:\ j2sdk1.4.2_03\b in

* Now you can just change directory to the '.class'
file location:

d: <ENTER>
cd d:\personal\jav a-ChartGen\TestCh art <ENTER>

* You may now invoke the application thus:

java -cp . TestChart

* Of course, if your application is 'packaged up', you may
need to do:

d: <ENTER>
cd \ <ENTER>

and invoke the application thus:

java personal.java-ChartGen.TestCh art

I hope this helps.

Anthony Borla

P.S.

The following link may be of help:

Re: Help with &quot;main&quot ; error

On Sun, 14 Dec 2003 05:03:25 GMT, "Anthony Borla"
<ajborla@bigpon d.com> wrote or quoted :
[color=blue][color=green]
>> Exception in thread "main" java.lang.NoCla ssDefFoundError :[/color][/color]

see http://mindprod.com/jgloss/errormess...SDEFFOUNDERROR

--
Canadian Mind Products, Roedy Green.
Coaching, problem solving, economical contract programming.
See http://mindprod.com/jgloss/jgloss.html for The Java Glossary.

Re: Help with &quot;main&quot ; error


"Roedy Green" <look-at-the-website-for-actual-Roedy@mindprod. com> wrote in
message news:uqsntvko3m h94p1f59v59kl6p [email protected] om...[color=blue]
> On Sun, 14 Dec 2003 05:03:25 GMT, "Anthony Borla"
> <ajborla@bigpon d.com> wrote or quoted :
>[color=green][color=darkred]
> >> Exception in thread "main" java.lang.NoCla ssDefFoundError :[/color][/color]
>
> see http://mindprod.com/jgloss/errormess...SDEFFOUNDERROR
>[/color]

Well, I got the web site part right ;) !

Cheers,

Anthony Borla

Re: Help with &quot;main&quot ; error

In article <uFRCb.1839$D66 .1494@nwrdny03. gnilink.net>, "news" <[email protected]>
wrote:
[color=blue]
> c:\j2sdk1.4.2_0 3\bin\java d:\personal\jav a-ChartGen\TestCh art.class[/color]

When you use the java command, you don't specify ".class"--it is assumed
and the period makes java think its looking for a class inside of a
package, which you don't have.

You also don't have to specify full paths like that. (Maybe you're just
doing it in frustration at not getting it to work).

Just cd to the directory containing your classes and type

java TestChart

--
|\/| /| |2 |<
mehaase(at)sas( dot)upenn(dot)e du

Re: Help with &quot;main&quot ; error

news wrote:[color=blue]
> I use the command line as follows:
>
> c:\j2sdk1.4.2_0 3\bin\java d:\personal\jav a-ChartGen\TestCh art.class
>
> The full error message is as follows:
>
> Exception in thread "main" java.lang.NoCla ssDefFoundError :
> d:\personal\jav a-ChartGen\TestCh art/class
>
>
> I thought it may be the CLASSPATH, but all my class files are located in the
> same folder and I used the switch -classpath but the same error comes up.[/color]

You've got a few responses, but I don't think they clearly explain the
issue, so I'll pop in. The Java VM expects a class name as it argument.
A class name is:

1. NOT a filename for a class file.
2. NOT the same as a filename minus the extension.

Instead of any of the above, it's a fully qualified class name. That
means the identifier that you put after the 'class' keyword in the
source file where you wrote the class, prefixed by the dot-delimited
string of identifiers after your 'package' keyword, if there is one.
Any "path" information shouldn't be there, period.

The source of confusion is that there are also a few rules that relate
the name of a class to how it's found by the VM. Those are incidental.
The classpath (set by an environment variable or command line option, or
various other implicit rules) determines at a basic level where the
class is found. The class name is the parameter, and it doesn't
duplicate the purpose of the classpath.

For this reason, I think it's helpful to say "use the class name, not a
file name" and that it's potentially quite confusing to say "leave off
the extension". After all, your command would still not have worked
even without the extension. Why? Because it's still not the class
name.

--

The Easiest Way to Train Anyone... Anywhere.

Chris Smith - Lead Software Developer/Technical Trainer
MindIQ Corporation