To build off of what @Kumar Basapuram wrote:
Make a java class called "Wrapper.java".
package animals;
public class Wrapper {
public static void main(String[] args) {
SampleApp app=new SampleApp();
app.main(args);
}
}
Link this main method to the main method in the "SampleApp.scala" class.
package animals
class SampleApp {
def main(args: Array[String]){
var c = new Cow("Bessie", 100)
println(c.speak)
var h = new Horse("CJ", 50)
println(h.speak)
var s = new Sheep("Little Lamb", 25)
println(s.speak)
println(s.weigh)
println(h.weigh)
println(c.weigh)
}
}
Project with Java and Scala Classes Picture
Right Click on the Project ScalaPracticeCreation.
Click Export...
Click Runnable JAR file under the Java folder
Exporting Scala Class into a jar Executable Picture
Click Next >
Select Wrapper - ScalaPracticeCreations
Select Export destination to a place on your computer
Select "Extract required libraries into generated JAR" under the "Library
handling:" option
Click Finish
Run the file through the Eclipse IDE and it works.
Run it through the Command Prompt and it does not work.
Command Prompt Picture
To fix this remove the println methods from the "SampleApp.scala".
package animals
class SampleApp {
def main(args: Array[String]) {
var c = new Cow("Bessie", 100)
var h = new Horse("CJ", 50)
var s = new Sheep("Little Lamb", 25)
c.weigh().toString()
}
}
add "System.out.println(app.main(args));" to replace "app.main(args);" in the Wrapper.java class
package animals;
public class Wrapper {
public static void main(String[] args) {
SampleApp app=new SampleApp();
System.out.println(app.main(args));
}
}
Now reexport the program after running it.
success in the command prompt Picture
Now it works.
Here are the extra filler .scala classes. Note that the Demo.scala class is irrelevant.
Weight.scala:
package animals
abstract class Weight(size: Int) {
def weigh = "My size is " + size
}
Animal.scala:
package animals
abstract class Animal(name: String, weight: Int) extends Weight(weight){
def speak = name + " says " + sound
def sound: String
override def weigh() = "My name is " + name + " and I weigh: " + weight
}
Cow.scala:
package animals
class Cow (name: String, weight: Int) extends Animal(name,weight){
override def sound() = "mooooo"
}
Horse.scala:
package animals
class Horse (name: String, weight: Int) extends Animal(name,weight){
override def sound() = "neigh"
}
Sheep.scala:
package animals
class Sheep (name: String, weight: Int) extends Animal(name,weight) {
override def sound() = "baaaa"
}
Note that this may not be the best solution although it is a functional solution. Scala sbt may be a better solution: Scala sbt or this Scala sbt-assembly.
