Question

I am trying to export a SimpleSwingApplication as an executable JAR with Eclipse:

package gui

import scala.swing._

object Startup extends SimpleSwingApplication {
  // ...
}

However, when I choose Export…/Java/JAR file and come to the part where I have to pick the Main class, Eclipse doesn’t seem to be able to find one. Manually typing in gui.Startup doesn’t help.

I thought maybe that’s because Startup is an object instead of a class, or maybe it has to do with inheriting the main method instead of providing one yourself. But even this simple code fails to export:

package gui

class Main {
  def main(args: Array[String]) {
    println("hello")
  }
}

What am I missing?

Answer 1

Try creating your own manifest file, and specify the main class yourself. When you export the jar file, eclipse will have a screen where you can select your own manifest file instead of generating one.

This example manifest should do the trick:

Manifest-Version: 1.0
Created-By: 1.6.0 (Sun Microsystems Inc.)
Main-Class: MyPackage.MyClass