“No main manifest attribute” when creating Kotlin

问题:

When creating a jar from my Kotlin code and running it, it says "No main manifest attribute". When looking at the manifest.mf, it has this content:

Manifest-Version: 1.0

When looking at the file in the source, it has this content:

Manifest-Version: 1.0
Main-Class: MyMainClass

When manually copying the source manifest to the jar, it runs perfectly.

Screenshot of my artifact settings

回答1:

If any of the dependent jars has a MANIFEST.MF file, it will override your custom one which defines the Main-Class.

In order to address this problem you should do the following:

• Disable the alphabetical ordering
• Change items ordering so that item which has META-INF/MANIFEST.MF file is the first in the list
• Your custom MANIFEST.MF will be picked up by IntelliJ IDEA and displayed for the jar artifact.

See the related issue for more details.

You can also use Gradle or Maven to generate the fat jar instead.