Groovy class non-public variables not visible to Java class

Question

I have two groovy classes in the same package:

class GTest {
  static Void main(args) {
    println G.newInstance().var // $> available
  }
}

class G {
  String var = "available"
}

When I have a similar reference to G from a java class in the same package var is no longer visible:

public class JTest {
  public static void main(String[] args) {
    G g = new G();
    System.out.println(g.var);  // $> The field G.var is not visible
  }
} 

When I make var explicitly public in the groovy class, JTest can access it. Is property scope different depending on the type of caller?

Answer 1

Groovy generates getters and setters for class properties. When you leave the modifiers off the field definition, it is actually creating the property as a private field and generating the accessor and mutator methods.

When using Groovy, calling 'g.var' actually calls the accessor (i.e. 'g.getVar()'); it is just allowing you to use the property access style.

If your Java class called 'g.getVar()' it will be able to access the data.

See Groovy Beans for a more lengthy explanation.