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NoClassDefFoundError msg

Posted on 2003-11-29
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Last Modified: 2010-03-31
I have WebCrawler.java and CrawlerExcpetion.java under c:\src\dkim18\crawler\ and I have WebCrawler.class and CrawlerExcpetion.class under c:\classes\dkim18\crawler\. When I run this program under c:\classes\dkim18\crawler\ dir, I have the following error msg:

Exception in thread “main” java.lang.NoClassDefFoundError: c:\classes\dkim18\crawler\

Why am I having this error?

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Question by:dkim18
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Expert Comment

by:CEHJ
ID: 9843065
Have you compiled all the classes?
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LVL 86

Expert Comment

by:CEHJ
ID: 9843079
Please post the full error message too:

>>Exception in thread “main” java.lang.NoClassDefFoundError:

misses out the most important piece of info (the class name)
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Expert Comment

by:objects
ID: 9843267
Ensure c:\classes is in your classpath, and you are specifying the full classname:

java dkim18.crawler.WebCrawler
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Expert Comment

by:objects
ID: 9843272
or you can specify the classpath on the command line:

java c:\classes;%classpath% dkim18.crawler.WebCrawler
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Author Comment

by:dkim18
ID: 9843372
Have you compiled all the classes?
>>yes

Please post the full error message too:
>>Exception in thread “main” java.lang.NoClassDefFoundError: c:\classes\dkim18\crawler\

when I run this :
javac -d classes -sourcepath src -classpath classes src\dkim18\crawler\WebCrawler.java

I got class files under c:\classes\dkim18\crawler\ and run program in this dir.
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Accepted Solution

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objects earned 100 total points
ID: 9843439
> javac -d classes -sourcepath src -classpath classes src\dkim18\crawler\WebCrawler.java

A lot easier to compile from the same directory as the source files :)
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Expert Comment

by:maheshexp
ID: 9844106
move to directory ..\src and type this command

java -cp "." src.dkim18.crawler.WebCrawler.java
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LVL 92

Expert Comment

by:objects
ID: 9844131
As i mentioned above:

java c:\classes;%classpath% dkim18.crawler.WebCrawler

will work from any directory.
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LVL 86

Expert Comment

by:CEHJ
ID: 9845105
Running with this command line:

>>java c:\classes;%classpath% dkim18.crawler.WebCrawler

Will mean that your source file for WebCrawler should start with

package dkim18.crawler;
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Expert Comment

by:objects
ID: 9846447
pretty sure it already does, but if theres a problem it can be dealt with when this problem is solved.
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Expert Comment

by:objects
ID: 9861433
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