I came across this weird (in my opinion) behavior today. Take this simple Test class:

public class Test {

public static void main(String[] args) {
    Test t = new Test();
    t.run();
}

private void run() {
    List<Object> list = new ArrayList<Object>();
    list.add(new Object());
    list.add(new Object());
    method(list);
}

public void method(Object o) {
    System.out.println("Object");
}

public void method(List<Object> o) {
    System.out.println("List of Objects");
}
}

It behaves the way you expect, printing "List of Objects". But if you change the following three lines:

List<String> list = new ArrayList<String>();
list.add("");
list.add("");

you will get "Object" instead.

I tried this a few other ways and got the same result. Is this a bug or is it a normal behavior? And if it is normal, can someone explain why?

Thanks.