Collections.emptyMap() isn't picking up the correct type

Question

I've got the following code:
public String toString(Map<String, String> args);
public String toString()
  return toString(Collections.emptyMap());
}this gives me a compiler error:
Cannot find symbol: toString(java.util.Map<java.lang.Object,java.lang.Object>)
In other words, it is picking up the wrong generic types. If, however, I use the following code:
public String toString()
  Map<String, String> t = Collections.emptyMap();
  return toString(t);
}it works fine. Any ideas why?
Thanks,
Gili

Answer 1

Cannot find symbol:
toString(java.util.Map<java.lang.Object,java.lang.Obje
ct>)
In other words, it is picking up the wrong generic
types. Apparent the compiler is not infering the types from the method parameters. I'm not sure that this is the correct behavior, but it would seem to me that it would be difficult to implement this kind of type inference correctly.
If it did infer the type from the method declaration, then if you later add a toString(Map<Object, Object>) what should the compiler do? Should it change which method is called? This would be create a binary compatiblity issue which I think was intentionally avoided.