Need help with SDK

[Allan Robertson]

Hello

I've downloaded the Java SDK 1.4.0 from Sun's website in the hope to
learning Java, however when I compile my *.java files this (at most times)
works fine, however when I run the *.class file using java.exe I get this
error message.

D:\jdk1.3\bin>java FirstLine.class

Exception in thread "main" java.lang.NoClassDefFoundError: FirstLine/class

I'm using Windows XP Pro with Java Runtime 1.4.0.
Can anyone help me? Any help would be great.
Thanks

[Randall R Schulz]

Allan,

Newbie mistake #23: The argument to the Java launcher (the "java"
command) takes _class_ names, not class _file_ names as arguments.

By including the ".class" suffix you instructd the Java launcher to
invoke the "main" entry point in the class named "FirstLine.class"
while I'm sure the class you wrote is called simply "FirstLine".

Also, get the latest J2SDK, which is now 1.4.2. Bugs are routinely
fixed, performance improved and library API enhancements added.

Similar complaints ("java.lang.NoClassDefFoundError" can result from
class-path and package naming problems. Be sure you understand these
concepts and the java launcher options and environment variables that
pertain to locating class files.

Good luck.

Randall Schulz
Allan Robertson wrote:

Hello

I've downloaded the Java SDK 1.4.0 from Sun's website in the hope
to learning Java, however when I compile my *.java files this (at
most times) works fine, however when I run the *.class file using
java.exe I get this error message.

D:\jdk1.3\bin>java FirstLine.class

Exception in thread "main" java.lang.NoClassDefFoundError:
FirstLine/class

I'm using Windows XP Pro with Java Runtime 1.4.0. Can anyone help
me? Any help would be great.

Thanks

[Randall R Schulz]

Phil,

There is a convention in the Sun Java tools to map package nesting
structures (with package names separated by dots, of course) to
directories separated by slashes. That's what you're seeing in that
exception diagnostic.

Randall Schulz
Phil... wrote:

A minor tweak on your otherwise excellent explanation. Note the
error message says FirstLine/class It thinks the dot means to go to
a subdirectory similar to what is done with import statements.

[Allan Robertson]

Thanks for your help, the code compiles fine now. I took your advice and
downloaded the 1.4.2_01 SDK fron Sun. Thanks :)

"Randall R Schulz" <rr******@cris.com> wrote in message
news:RG********************@typhoon.sonic.net...

Allan,

Newbie mistake #23: The argument to the Java launcher (the "java"
command) takes _class_ names, not class _file_ names as arguments.

By including the ".class" suffix you instructd the Java launcher to
invoke the "main" entry point in the class named "FirstLine.class"
while I'm sure the class you wrote is called simply "FirstLine".

Also, get the latest J2SDK, which is now 1.4.2. Bugs are routinely
fixed, performance improved and library API enhancements added.

Similar complaints ("java.lang.NoClassDefFoundError" can result from
class-path and package naming problems. Be sure you understand these
concepts and the java launcher options and environment variables that
pertain to locating class files.

Good luck.

Randall Schulz
Allan Robertson wrote:

Hello

I've downloaded the Java SDK 1.4.0 from Sun's website in the hope
to learning Java, however when I compile my *.java files this (at
most times) works fine, however when I run the *.class file using
java.exe I get this error message.

D:\jdk1.3\bin>java FirstLine.class

Exception in thread "main" java.lang.NoClassDefFoundError:
FirstLine/class

I'm using Windows XP Pro with Java Runtime 1.4.0. Can anyone help
me? Any help would be great.

Thanks

[Saurabh Manohar]

Have you added '.\' to the CLASSPATH variable
add the line
SET CLASSPATH=.';%CLASSPATH%
in your c:\autoexec.bat
HTH
Saurabh
"Allan Robertson" <no****@nospam.com> wrote in message
news:xj**************@news-binary.blueyonder.co.uk...

Hello

I've downloaded the Java SDK 1.4.0 from Sun's website in the hope to
learning Java, however when I compile my *.java files this (at most times)
works fine, however when I run the *.class file using java.exe I get this
error message.

D:\jdk1.3\bin>java FirstLine.class

Exception in thread "main" java.lang.NoClassDefFoundError: FirstLine/class

I'm using Windows XP Pro with Java Runtime 1.4.0.
Can anyone help me? Any help would be great.
Thanks