Java catch blocks use static binding?
instanceof, java
Solution
Yes. It's correct. Overloads are always resolved statically.
Neither of your latter 2 examples will compile as `e`'s static type is `Exception`, and neither of your overloads accept that type.
Edit:
Note that your final example isn't really a direct analog to the try/catch block. In the try/catch you have two variables called `e`: one for each catch, and their static types are `InvalidResourceException` and `ResourceException` respectively. In your final example you have a single variable named `e`, and its static type is `Exception`. If you added new variables and assigned to them with a cast then you'd get the same behavior as your try/catch (though you'd have to lose the final else branch).
Problem
Assume InvalidResourceException is a subclass of ResourceException. Define two methods: ``` void handleException(ResourceException e) { System.out.println("ResourceException " + e.toString()); } void handleException(InvalidResourceException e) { System.out.println("InvalidResourceException " + e.toString()); } ``` Now the following code: ``` try { throw new InvalidResourceException("invalid resource"); } catch (ResourceException e) { handleException(e); } ``` prints this: ``` ResourceException: com.myPackage.InvalidResourceException: invalid resource ``` But the following code: ``` try { throw new InvalidResourceException("invalid resource"); } catch (InvalidResourceException e) { handleException(e); } catch (ResourceException e) { handleException(e); } ``` prints this: ``` InvalidResourceException: com.myPackage.InvalidResourceException: invalid resource ``` This is with Sun's JDK 1.5.0_15. Is this consistent with the Java standard? What should this code do? ``` Exception e = new InvalidResourceException("invalid resource"); handleException(e); ``` What should this code do? ``` Exception e = new InvalidResourceException("invalid resource"); if (e instanceOf ResourceException) { handleException(e); } else if (e instanceOf InvalidResourceException) { handleException(e); } else { handleException(e): } ```