Final variables and try blocks

Question

If you tried to initialize a final variable within a try block, you would get a compile-time error.
Here's an example class:
class Example {
    private final String example;
    public Example() {
        try {
            example = "Example";
        } catch (Exception e) {
            // Just an example.
}Obviously you wouldn't need to try-catch something like this (it's a stupid example - I know) , but the point is, the code wouldn't compile, and would return an error saying something like "example may not have been initialized".
So I've got two questions. Why is this, and is there any way around it?
Thanks in advance :)

Answer 1

Why is thisThe actual error message is "The blank final field example may not have been initialized". The Java compiler insists that all the fields have some actual value when a constructor has done its thing. Nonfinal fields will have the "default" value of null, but this is not so for final fields: if they had a default value, you couldn't change them from that default because they're final!
Once you enter a try block the compiler has no way of knowing that the assignment line will ever get carried out. Some exception might occur and the example field would be left uninitialised ie having no value whatsoever, not even null.
is there any way around it?In the catch part you could throw the exception and let the caller deal with it.
Or you could try and assign some value to example within the catch part. Now the compiler will complain "The final field example may already have been assigned". Supposing you wanted it to end up as null in this case (it's not clear why though... But you may have a sensible "default" if for example a file can't be written to or some other exceptional state has occured)
class Example {
    private final String example;
    public Example() {
        String str;
        try {
            str = "Example";
        } catch (Exception e) {
            str = null;
        example = str;
}