Dealing with phone numbers formats

I think I'm facing a paradox here.

What I'm trying to do is when I receive/make a call, I have the number, so I need to know if its an international number, if its a local number, etc.

The problem is:

1. For me to know if a number is international, I need to parse it and check its length, but, the length differs from country to country, so, should I do a method that parses and rec开发者_JS百科ognizes for each country? (Unfunctional in my opinion);
2. For me to know if its a local number, I need the area code, so I have to make the same thing, parse the number and check the lenght, get the first numbers based on the area code lenght;

Its kinda hard to find the solution for this. The library libphonenumber offers a lot of usefull classes, but the one that I thought that could help me, took me to another paradox.

The method phoneUtil.parse(number, countryAcronym) returns the number with its country code, but what it does is, if I pass the number with the acronym "US" it return the number with country code '1', now if I change the acronym to "BR" it changes the number and return '55' that is the country code for Brazil. So, anyways, I need the country acronym based on the number I get.

EX:

numberReturned = phoneUtil.parse(phoneNumber, "US");
phoneUtil.format(numberReturned, PhoneNumberFormat.INTERNATIONAL);

The above code, returns the number with the US country code but now if I change the "US" to any other country acronym it will return the same number but with the country code of that country.

I know that this lib is not supposed to guess from which country the number is (THAT WOULD BE AWESOME!!), but thats what I need.

This is really making my mind goes crazy. I need good advices from the wise mages of SO.

If you please could help me with a good decision, I'd be so thankfull.

Thanks.

PS: If you already use libphonenumber and has more experience with this, please guide me on which class to use, if there is one capable of solving this problem. =)

1) The second parameter to phoneUtil.parse must match the country you're currently in - it's used if the phone number received does not include an international prefix. That's why you get different results when you change the parameter: the phone number you pass it does not contain such a prefix, so it just uses what you've told it.

Any parsing solution set to determine if the phone number is international or not will need to be aware of this: depending on the source, even a national number may be represented with the international dialing prefix (usually abstracted as +, since it differs between countries, but this is not guaranteed).

2) For area code parsing, there is no universal standard; some countries don't use them, and even within a country, area codes may have differing lengths (e.g. Germany). I'm not aware of an international library for this - and a quick search doesn't find anything (though that doesn't mean one does not exist). You might need to roll your own here; if you only need to support a single country, this shouldn't be too hard.