Could not find or load main class: c:\java\HelloWorldApp

[Atticus]

The title of this post is the error that appeared when I attempted to run the Hello World application as outlined in the Java Tutorials.

My source file was HelloWorldApp.java (cut and pasted from the tutorial)

I compiled it with the command : javac HelloWorldApp.java

It produced a file HelloWorldApp.class

I then attempted to run the application with the command : java HelloWorldApp

It then produced the above error. I am aware that this particular problem was the subject of another posting but I cannot figure out what the proposed solution was. Can anyone help?

[Junky]

java -cp . HelloWorldApp

Try the above command (make sure you get the spaces correct). If it works then read about classpath.

[Atticus]

I used the command : java -cp . HelloWorldApp

However, the error appeared exactly as before.

[Junky]

In that case your HelloWorldApp class is not in that directory.

[Atticus]

Hi Junky

Thank you for being patient.

The file HelloWorldApp.class resides in C:\java

I abbreviated the command for purposes of clarity.

The full command was C:\Program Files\java\jdk1.7.0\bin\java - cp . C:\java\HelloWorldApp

[Junky]

Go to the directory where you .class file is and type the command to run your program.

[chinna]

please share your code...

[Atticus]

Hi Junky,

Problem solved
Both instructions - java HelloWorldApp and java -cp . HelloWorldApp now work.
Apparent problem was that the instructions would not tolerate a full description of where the HelloWorldApp class file resided

A curiosity : I used a DOS PATH statement (as used in autoexec.bat files) to pick up the location of java.exe and javac.exe and make them available in any directory. Is this how it is usually done nowadays?

Thanks again!

[JosAH]

A curiosity : I used a DOS PATH statement (as used in autoexec.bat files) to pick up the location of java.exe and javac.exe and make them available in any directory. Is this how it is usually done nowadays?

Remember: javac compiles files and java runs classes; the fact that those classes can be stored in files is coincidental. java uses the current working directory as a classpath (so -cp . is not necessary on a MS Windows system). It depends on the classloader where and how classes are found; the 'normal' system class loader can find the classes in files or in .jar file entries but nothing forbids other class loaders to load classes from databases or by emailing some super user and asking them to send the class over the wire. The classpath is just used by the default class loader and is a list of directories and .jar files that have to be searched for class files. Package names in class names are mapped to subdirectories.

kind regards,

Jos

[kd7vea]

I just wanted to chime in here, and say that your response helped me. I have been fighting with my classpath trying to get it right, but atleast now I know that everything else worked.
Thanks
Jake

[DarrylBurke]

What's with waking the zombies? Closing this old, weary thread.

db