I am creating a jar file for an application that has several classes. I created the jar file with the command "jar cf app.jar *.class". When I try to run the jar file, I type in "java -jar app.jar" and I get the error
"Failed to load Main-Class manifest attribute from app.jar". How do I either modify the manifest file to give it the attribute it wants or how do I create the jar file with the needed attribute?