"no main manifest attribute" error in intellij when executing jar

Question

I'm working on a kotlin project that I want to execute as a jar. This is all done in IntelliJ Idea and I went about making the jar using the artifacts.

The process I followed was (as illustrated by an Idea guide):

1. Add artifact (as jar) from project structure
2. Build jar
3. Run jar

After this, I get a

'no main manifest attribute, in ____.jar'

What I have tried after reading several stack overflow questions:

• Checking that the manifest file is in the correct folder and has the correct path in the artifact
• Adding code to the build.gradle file for the jar->manifest portion
• Trying the method of moving the manifest stuff into a resources folder
• Checking that the jar exists
• Moving the manifest stuff into a different folder (java,kotlin,out folders)
• Making sure that the manifest file is in the correct format

All of the above has not worked.

Something that is confusing to me is that, even when I alter the manifest file to be in "incorrect" format, it still gives the same error. The path stated in the artifact's details is correct yet there is no difference even when I purposely input incorrect items in the manifest file. Not sure if that is the"real" problem but I'm also not sure how to fix that as well

Answer 1

None of the solutions worked for me.

I solved it in this way:
When setting up the artifact, change:
Meta-inf: (...)\src\main\ (you must remove "java")

Also, there was a problem with resources, solved this way:
When setting up the artifact:
Output Layout > Add copy of > Directory content > resources.

That's all!

Answer 2

while creating the exeutable jar file explicitly create a mainfest.txt file that should be in order of the directory structure and mainfest.txt file should contain only one line (Main-Class:name of the class containg main method)then run the jar tool

Answer 3

For anyone that may have encountered this problem in intellij and did not find a solution in any other posts, what helped me was

1. Navigating to Project Structure
2. Going to the Artifacts tab
3. Explicitly adding a new META-INF/ directory in my jar
4. Adding the created MANIFEST.MF file to the META-INF/ in the jar FROM THE ARTIFACTS TAB
5. Rearranging the order for the META-INF/ to be at the top
6. Building and running

The end result looked like this