Java Could not find or load main class when running jar file

Question

I have a springboot application, it runs just fine in intellij. I'm trying to create an executable jar to run the application on other machines. I followed this

tutorialhttps://www.jetbrains.com/idea/guide/tutorials/hello-world/packaging-the-application/

down to every step, and managed to build my jar. but when i try to run the jar with

java -jar nameofjar.java

I get a Could not find or load main class error. I unzipped the jar file with java c and the classpath correctly points to the main class, so im really lost as to what i have to fix here to get java to detect the main class.

I've tried a bunch of solutions from here:

Error: Could not find or load main class in intelliJ IDE

such as deleting .idea or Rebuild Project or doing mvn clean package but nothing seems to work.

Using java -c to open the jar file and verify that the main classpath is indeed correct

Main class and file structure:

This run config works perfectly fine in intellij

here is my manifest.mf:

Manifest-Version: 1.0
Main-Class: com.owl.PosApi.OwlPosApiApplication

See https://www.baeldung.com/deployable-fat-jar-spring-boot. — CrazyCoder, Nov 29 '22 at 16:58
@CrazyCoder this worked, instead of following the tutorial i followed all i had to do in the end was run mvn clean install and find the jar file in the target folder, not out folder. Could you copy paste your comment as an answer so i can set it as answer, thanks so much. — Oirampok, Nov 29 '22 at 17:35

score 1 · Accepted Answer · answered Nov 29 '22 at 18:25

If you build jar artifact using IntelliJ IDEA, it may be incomplete or manifests from the other included dependencies can override your custom one with the main class defined.

Java Could not find or load main class when running jar file

1 Answers1