How to find out what a string contains?

Question

I'm in the process of writing an XML parser for a project that I am working on. There will be one field in the XML that can be used to store an int, a date, or a string. I need to figure out a way to determine if that field contains an int, a date, or a string without modifying the XML at all. Meaning I can't just put an indicator in the XML itself. So given the string of data from the xml, how do I figure out what it is so that I can convert it to that type?
Any help would be appreciated as I don't have much time left to work on this.

Answer 1

How are you going to be able to tell?
There will be one field
in the XML that can be used to store an int, a date,
or a string. "20010101" fits all three. In the absence of any other information, there's no way to tell what the sender meant the type to be.
Now, if you assume some formatting information, then you have a chance. Let's say that "dates" MUST be in the format "YYYY-mm-dd hh:MM:ss". Use SimpleDateFormat and Calendar and try to parse the string. If it works - it's a Date.
If it doesn't work - try to parse it as an Integer. If it works - it's an int.
If THAT doesn't work - give up and just use the String.
Does that help?
Grant