java runtime problems
Johnny Danger
java apps on mepis linux (ver. 3.4-3). I have installed jdk 1.6.0 and
i am having runtime error problems. It seems like a simple matter,
but i do not know how to solve the problem i am having. I have
compiled the following code directly from the sun website...
package start;
/*
* HelloWorldSwing.java requires no other files.
*/
import javax.swing.*;
public class HelloWorldSwing {
/**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("HelloWorldSwing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Add the ubiquitous "Hello World" label.
JLabel label = new JLabel("Hello World");
frame.getContentPane().add(label);
//Display the window.
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
when i compile, nothing seems to be wrong...
Aesotericon@5[HelloWorldSwing]$ ls
HelloWorldSwing.java
Aesotericon@5[HelloWorldSwing]$ /home/Aesotericon/Documents/jdk1.6.0/
bin/javac HelloWorldSwing.java
Aesotericon@5[HelloWorldSwing]$ ls
HelloWorldSwing$1.class HelloWorldSwing.class HelloWorldSwing.java
Aesotericon@5[HelloWorldSwing]$
when i try to run the program the following happens...
Aesotericon@5[HelloWorldSwing]$ /home/Aesotericon/Documents/jdk1.6.0/
bin/java HelloWorldSwing
Exception in thread "main" java.lang.NoClassDefFoundError:
HelloWorldSwing (wrong name: start/HelloWorldSwing)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
at
java.security.SecureClassLoader.defineClass(SecureClassLoader.java:
124)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:
260)
at java.net.URLClassLoader.access$000(URLClassLoader.java:56)
at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:
276)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:
319)
Aesotericon@5[HelloWorldSwing]$ /home/Aesotericon/Documents/jdk1.6.0/
bin/java .HelloWorldSwing
Exception in thread "main" java.lang.NoClassDefFoundError: /
HelloWorldSwing
Aesotericon@5[HelloWorldSwing]$ unset CLASSPATH
Aesotericon@5[HelloWorldSwing]$ /home/Aesotericon/Documents/jdk1.6.0/
bin/java HelloWorldSwing
Exception in thread "main" java.lang.NoClassDefFoundError:
HelloWorldSwing (wrong name: start/HelloWorldSwing)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
at
java.security.SecureClassLoader.defineClass(SecureClassLoader.java:
124)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:
260)
at java.net.URLClassLoader.access$000(URLClassLoader.java:56)
at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:
276)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:
319)
Aesotericon@5[HelloWorldSwing]$ /home/Aesotericon/Documents/jdk1.6.0/
bin/java .HelloWorldSwing
Exception in thread "main" java.lang.NoClassDefFoundError: /
HelloWorldSwing
As you all see, I have tried several methods of running the program,
but it will not work. I feel like a simpleton, but does anyone have
any suggestions? It seems that java is having a hard time finding
my .class file. I dunno...
J.P.
Gordon Beaton
> when i try to run the program the following happens...
>
> Aesotericon@5[HelloWorldSwing]$ /home/Aesotericon/Documents/jdk1.6.0/
> bin/java HelloWorldSwing
> Exception in thread "main" java.lang.NoClassDefFoundError:
> HelloWorldSwing (wrong name: start/HelloWorldSwing)
Because of the package statement ("package start") the name of the
class is "start.HelloWorldSwing". That's what java is trying to tell
you with the somewhat cryptic message above.
Either remove the package statement from the source code (and
recompile), or run it like this instead:
java start.HelloWorldSwing
This is a good introduction to using Java packages:
http://www.yoda.arachsys.com/java/packages.html
/gordon
--
Johnny Danger
voila! thank you!
Andrew Thompson
> On Sep 21, 12:45 am, Johnny Danger <jpaez1...@gmail.com> wrote:
> > On Sep 21, 12:04 am, "Andrew Thompson" <u32984@uwe> wrote:
>
> > > Johnny Danger wrote:
> > > >Hello all. I have a very simple problem.
Being a multi-poster is a fairly siple problem to
fix. Your other problems, incluung the over
inflated sense of self entitlement, are more
tricky.
> > >I am seeking to develop
> > > >java apps on mepis linux (ver. 3.4-3). I have installed jdk 1.6.0 and
> > > >i am having runtime error problems.
> > > ..
> > > >package start;
> > > ..
> > > >Aesotericon@5[HelloWorldSwing]$ /home/Aesotericon/Documents/jdk1.6.0/
> > > >bin/java HelloWorldSwing
>
> > > The fully qualified name of this class is 'start.HelloWorldSwing'.
>
> > > Perhaps you might run it using
> > > ..java start.HellowWorldSwing
>
> > > OTOH - I guess then you will be getting a 'wrong package'
> > > or similar error.
>
> > > As an initial test, I would recommend commenting out
> > > or removing the package statement, then recompiling it
> > > and trying again with.
> > > ..java HelloWorldSwing
>
> > > Then you might (later) figure how to compile and run
> > > packaged code.
> > > ..
>
> > > >As you all see, I have tried several methods of running the program,
> > > >but it will not work. I feel like a simpleton, but does anyone have
> > > >any suggestions? It seems that java is having a hard time finding
> > > >my .class file. I dunno...
>
> > > For best help, it is advisable to use the more
> > > common forms of expressions (no 'slang').
> > > Note that *many* of the people who contribute
> > > to these forums speak Engilsh as a Second
> > > (3rd.. etc.) Language, and might not recognise
> > > 'dunno' as 'do not know'. Also, many of us who
> > > *do* speak English as a native tongue, simply
> > > don't like seeing such abbreviations.
>
> > > That being said, I myself occasionally use slang
> > > words, but usually only in replies to people whom
> > > I am confident would understand what I mean.
>
> > > (Oh, and the word 'I' should always be Upper Case
> > > in English - *always*.)
...
> > please limit replies to those directly relating to the conversation at
> > hand...
Pleas get yourself a help-desk. These are
discussion forums.
> got a *useful* reply to this question on another thread.
Sure you did. Six minutes later than my
reply on your first thread, that pointed
out the same thing.
(Title changed, and x-posted to c.l.j.p./h.
in effots to combine the multi-post, with
follow-ups to c.l.j.h. only)
Andrew T.