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Could not find the main class

Hello. I entered

;C:\Program Files (x86)\Java\jre6\bin to my Path environment variable. I am running Vista Ultimate on 64 bits.


Then I went to the command prompt and entered

java weka.core.converters.CSVLoader data.csv > data.arff

I get a message:


C:\Users\william>java weka.core.converters.CSVLoader data.csv > data.arff
Exception in thread "main" java.lang.NoClassDefFoundError: weka/core/converters/
CSVLoader
Caused by: java.lang.ClassNotFoundException: weka.core.converters.CSVLoader
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClassInternal(Unknown Source)
Could not find the main class: weka.core.converters.CSVLoader.  Program will exi
t.

By the way, is there an easy way to copy from the Command Prompt?
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ksivananth
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you need to weka jar files/libraries into classpath...
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Gurvinder Pal Singh
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for the classNotFoundException:
You need to make sure that you are executing that java command just outside the 'weka' folder.
I am assuming that
1) class files are generated (no compilation errors)
2) required jars/libs are in classpath



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ASKER

Hi. Thank you for the help. I am confused. Do I need to edit my Path variable in some other way or my CLASSPATH variable? I do have Java installed in C:\Program Files (x86)\Java\jre6\bin

and I do have Weka installed at
C:\Program Files (x86)\Weka-3-7
Avatar of Gurvinder Pal Singh
Gurvinder Pal Singh
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what does "C:\Program Files (x86)\Weka-3-7" includes?
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ASKER

Hi. Here is a screen shot
weka.jpg
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Gurvinder Pal Singh
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i can see weka.jar file there. Is it added in the classpath?
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ASKER

In Environment Variables my CLASSPATH has
.;C:\Program Files (x86)\Java\jre6\lib\ext\QTJava.zip
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ASKER

Here is my directory
java.jpg
Avatar of Gurvinder Pal Singh
Gurvinder Pal Singh
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Add "C:\Program Files (x86)\weka.jar" also in the classpath.

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onyourmark

ASKER

Hello. I added

then tried
java weka.core.converters.CSVLoader data.csv > data.arff

I get

Microsoft Windows [Version 6.0.6001]
Copyright (c) 2006 Microsoft Corporation.  All rights reserved.

C:\Users\william>java weka.core.converters.CSVLoader data.csv > data.arff
Exception in thread "main" java.lang.NoClassDefFoundError: weka/core/converters/
CSVLoader
Caused by: java.lang.ClassNotFoundException: weka.core.converters.CSVLoader
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClassInternal(Unknown Source)
Could not find the main class: weka.core.converters.CSVLoader.  Program will exi
t.

C:\Users\william>
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onyourmark

ASKER

Sorry, I added

;C:\Program Files (x86)\weka.jar
Avatar of Gurvinder Pal Singh
Gurvinder Pal Singh
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try this
java -classpath "C:/Program Files (x86)/weka.jar" weka.core.converters.CSVLoader data.csv > data.arff

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onyourmark

ASKER

I get the same error
SOLUTION
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Hi. I am not sure how to locate that. I looked on the internet and find
http://weka.sourceforge.net/doc/weka/core/converters/CSVLoader.html
Avatar of Gurvinder Pal Singh
Gurvinder Pal Singh
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can you try this (both commands)

set CLASSPATH=%CLASSPATH%;C:\Program Files (x86)\weka.jar;
java weka.core.converters.CSVLoader data.csv > data.arff

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ASKER

Hi thanks. I tried that but I get the error on the second command.