Generic throws clause causes unreported exception

Question

I'm trying to pass a block to a ctor, which can throw an exception. The problem can be reproduced with this sample program.
interface Bar<X extends Exception> {
    void run() throws X;
public class Foo {
    public Foo() {}
    public <X extends Exception> Foo(Bar<X> bar) throws X {
        bar.run();
    public static <X extends Exception> Foo createFoo(Bar<X> bar) throws X {
        return createFoo2(bar); // ok
    public static <X extends Exception> Foo createFoo2(Bar<X> bar) throws X {
        Foo foo = new Foo();
        bar.run(); // ok
        return foo;
    public static <X extends Exception> Foo createFoo3(Bar<X> bar) throws X {
        return new Foo(bar);  // unreported exception X; must be caught or declared to be thrown
}createFoo and createFoo2 work fine, but createFoo3 fails to compile with javac. None of the examples raise a warning in IDEA. I'm running javac 1.5.0_07.
Is there a way to do this in Java 1.5, or is this a bug with javac?

Answer 1

BrianEgge wrote:
However, we know types inference works differently for methods vs constructors (15.12.2.8). This is why List<String> s = Collections.emptyList(); works, but List<String> s = new ArrayList<String>() generates an unchecked warning. Well, this is definitely not true.
According the the JLS, the throws clause shouldn't be handled differently.
8.8.5 Constructor Throws
The throws clause for a constructor is identical in structure and behavior to the throws clause for a method (�8.4.6).The JLS explicitely allows a constructor to be defined generic, and those parameters have a scope on the constructor definition including the parameter list (8.8.4 Generic Constructors).
Hence, I assume, this is a bug.