JSF Float Conversion

Question

I'm using JSF 1.2 with IceFaces 1.8 in a project here.

I have a page which is basically a big edit grid for a whole bunch of floating-point number fields. This is implemented with inputText fields on the page pointing at a value object with primitive float types

Now, as a new requirement sees some of the fields be nullable, I wanted to change the value object to use Float objects rather than primitive types. I didn't think I'd need to do anything to the page to accomodate this.

However, when I make the change I get the following error:

/pages/page.xhtml @79,14 value="#{row.targetValue}": java.lang.IllegalArgumentException: argument type mismatch

And

/pages/page.xhtml @79,14 value="#{row.targetValue}": java.lang.IllegalArgumentException: java.lang.ClassCastException@1449aa1

The page looks like this:

<ice:inputText value="#{row.targetValue}" size="4">
  <f:convertNumber pattern="###.#" />
</ice:inputText>

I've also tried adding in <f:convert convertId="javax.faces.Float" /> in there as well but that doesn't seem to work either! Neither does changing the value object types to Double .

I'm sure I'm probably missing something really simple but I've been staring at this for a while now and no answers are immediately obvious!

Answer 1

After some investigation (see eg here , here and here ) that <f:convertNumber> is the problem. It seems that the number it converts to is dependent on the input you give it - it could be an integer or a floating point number. In other words, it doesn't look at the target type - it just generates an instance of java.lang.Number. Which is hardly ideal, although I can't determine whether this is because somewhere I'm using an old version of JSF or EL or something like that.

There seem to be three solutions:

1. Use java.lang.Number as your value object type;
2. Write your own converter;
3. Don't use <f:convertNumber> .

Unfortunately #1 isn't an option for me for other reasons, and I don't want to write my own converter at the moment. However if I change the code to remove the convertNumber, everything seems to work OK. (I've also updated the value object type to Double which was suggested in one of the links I looked at).

That prevents the exceptions, and it looks like JSF is still doing what I want it to do. Just annoying that it seems you can't specify convertNumber and the convert type in the same instance.