Question

I’ve just made a game in netbeans. The Problem is that after builting the game. I’m not able to execute the jar file and getting the exception:
Failed to load Main-Class manifest attribute from
Game.jar

What to do???

Answer 1

For a JAR to be self-executable, you have to include the Main-Class line in a manifest.

I’m not a NetBeans user, but this is how it’s done.

Create a manifest.mf file:

Main-Class: YourGame
<newline>

Build the jar:
jar cmf manifest.mf Game.jar path/to/classes/*.class

You should now be able to to double-click on the JAR to run it (assuming Windows), or you can run it via the command line:

java -jar Game.jar

Of course, you can always run from the command line without the need for a manifest:

java -cp .;Game.jar YourGame