Question

I am trying to run a java based tool using a command line syntax as the following: java -cp archive.jar archiveFolder.theMainClassName.Although the class I am searching for, a main class, ‘theMainClassName’ is in the archive.jar and in the archiveFolder given at input, I keep getting the error that my class is not seen. Does anybody have any ideas concerning this problem? Thank you in advance

Answer 1

Here’s a concrete example of what does work, so you can compare your own situation.

Take this code and put it anywhere, in a file called MainClass.java. (I’ve assumed a directory called src later. Normally you’d arrange the source to match the package, of course.)

package archiveFolder;  public class MainClass {     public static void main(String[] args)     {         System.out.println('I'm MainClass');     } } 

Then run each of these commands:

# Compile the source javac -d . src/MainClass.java  # Build the jar file jar cf archive.jar archiveFolder  # Remove the unpackaged binary, to prove it's not being used rm -rf archiveFolder # Or rmdir /s /q archiveFolder on Windows  # Execute the class java -cp archive.jar achiveFolder.MainClass 

The result:

I'm MainClass 

How are you building your jar file? Is the code in the appropriate package?