Reference to an object of any class that implements two or more given interfaces

Given any interface I, it is possible to declare a variable that holds a reference to any object of a class C that implements I:

I i = new C();

I want to do something similar. Given two interfaces, I want to declare a variable that holds a reference to any object of a class that implements both interfaces:

interface Foo { void foo(); }
interface Bar { void bar(); }

class Humpty implements Foo, Bar {
  public void foo() { System.out.println("Humpty.foo()"); }
  public void bar() { System.out.println("Humpty.bar()"); }
}

class Dumpty implements Foo, Bar {
  public void foo() { System.out.println("Dumpty.foo()"); }
  public void bar() { System.out.println("Dumpty.bar()"); }
}

public class Program {
  public static void main(String[] args) {
    // I actually have no idea what the syntax should be.
    Random random = new Random();
    // Fix: I previously used <? extends Foo, Bar>, thanks Jon Skeet and vijucat
    <? extends Foo & Bar> foobar;
    if (random.nextBoolean())
      foobar = new Humpty();
    else
      foobar = new Dumpty();
    foobar.foo();
    foobar.bar();
  }
}

I have tried the above snippet, but <? extends Foo, Bar> causes a compilation error. What should the correct syntax be? I would like to know if this is possible in other statically typed JVM languages, too: Scala, Kotlin, Ceylon, etc.