[GROOVY-2634] Using Java Generics

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.5.6, 1.6-beta-1
• Assignee: Jochen Theodorou
• Reporter: ccadete
• Created: 26/Feb/08 08:06
• Updated: 24/Apr/08 08:22
• Resolved: 24/Apr/08 08:22

Description

The code

class BaseA implements Comparable {
    
    int index
    
    public BaseA(){
        index = Math.random() * 10
        println index
    }

    public int compareTo(Object a){
        return new Integer(index).compareTo(a.index)
    }

}


def a = new BaseA()
def b = new BaseA()

println( a.compareTo(b) )

Works just fine but if i use the generics version like:

class BaseA implements Comparable<BaseA> {
    
    int index
    
    public BaseA(){
        index = Math.random() * 10
        println index
    }

    public int compareTo(BaseA a){
        return new Integer(index).compareTo(a.index)
    }

}


def a = new BaseA()
def b = new BaseA()

println( a.compareTo(b) )

Gives the error :

Exception thrown: org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed, Script85: 4: Can't have an abstract method in a non-abstract class. The class 'BaseA' must be declared abstract or the method 'int compareTo(java.lang.Object)' must be implemented.

Groovy is not replacing the generic type BaseA in the compareTo parameter.