Solved
com.johnny.Main is your program's entry point.
...
...
...
jar {
manifest {
attributes(
'Main-Class': 'com.johnny.Main'
)
}
}
...
...
...
https://stackoverflow.com/questions/43081894/gradle-output-jar-has-no-main-class/
https://stackoverflow.com/questions/32567167/gradle-no-main-manifest-attribute