Question

I created a unit test :

new Callable() {
@Override
public Object call() throws
         .....

I have received warning in Eclipse:

Callable is a raw type. References to generic type Callable<V> 
should be parameterized

Should I write code like:

new Callable<Object>()  

for eliminating warning, or not?
It seems only junit test and there is no sense to add additional code…
Thanks.

Answer 1

If your operation doesn’t return a value (, or there’s nothing meaningful to return). You should use java.lang.Void as type parameter.

new Callable<Void>() {

  public Void call() throws Exception {
    // do work
    return null; // <-- This statement is required.
  }

}