Obtaining State abbreviation from getAdminArea();

Question

I\'ve attempted two different ways in trying to obtain the city name as well as the state abbreviation only from the Address class, with no luck. The first is returning the

Answer 1

Here is a combined and modified version of Bourne and pellyadolfo's answers. It first tries to map the full state name to a state code (works for Canadian provinces too, and is less error prone than regex), and if that doesn't work then it falls back on the regex solution (which has the potential for error, hence why I prefer it as a backup solution, but can work with different languages or countries).

The regex solution has been improved to include a sanity check at the beginning, and has a more advanced regex to eliminate needing to manually filter out "USA" (this allows Canadian addresses to work). It also removes the "toupper()" call which has a side effect of converting "St" (short for "street") into "ST" which can cause a false match.

import android.location.Address;
import android.util.Log;

import java.util.HashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class StateNameAbbreviator {
    private static final String TAG = "StateNameAbbreviator";

    static private Map mStateMap = null;

    static public String getStateAbbreviation(Address address) {
        if (address == null) {
            return null;
        }

        populateStates();

        String stateCode = mStateMap.get(address.getAdminArea());
        if (stateCode == null) {
            Log.d(TAG, "State mapping failed, parsing from address");
            stateCode = parseStateCodeFromFullAddress(address);
            if (stateCode == null) {
                Log.d(TAG, "Could not parse state from address");
            }
        }
        else {
            Log.d(TAG, "Successfully mapped " + address.getAdminArea() + " to " + stateCode);
        }

        return stateCode;
    }

    static private String parseStateCodeFromFullAddress(Address address) {
        if ((address == null) || address.getMaxAddressLineIndex() < 0) {
            return null;
        }

        String fullAddress = "";
        for(int j = 0; j <= address.getMaxAddressLineIndex(); j++) {
            if (address.getAddressLine(j) != null) {
                fullAddress += " " + address.getAddressLine(j);
            }
        }

        Log.d(TAG, "Full address: " + fullAddress);

        Pattern pattern = Pattern.compile("(?();
            mStateMap.put("Alabama", "AL");
            mStateMap.put("Alaska", "AK");
            mStateMap.put("Alberta", "AB");
            mStateMap.put("American Samoa", "AS");
            mStateMap.put("Arizona", "AZ");
            mStateMap.put("Arkansas", "AR");
            mStateMap.put("Armed Forces (AE)", "AE");
            mStateMap.put("Armed Forces Americas", "AA");
            mStateMap.put("Armed Forces Pacific", "AP");
            mStateMap.put("British Columbia", "BC");
            mStateMap.put("California", "CA");
            mStateMap.put("Colorado", "CO");
            mStateMap.put("Connecticut", "CT");
            mStateMap.put("Delaware", "DE");
            mStateMap.put("District Of Columbia", "DC");
            mStateMap.put("Florida", "FL");
            mStateMap.put("Georgia", "GA");
            mStateMap.put("Guam", "GU");
            mStateMap.put("Hawaii", "HI");
            mStateMap.put("Idaho", "ID");
            mStateMap.put("Illinois", "IL");
            mStateMap.put("Indiana", "IN");
            mStateMap.put("Iowa", "IA");
            mStateMap.put("Kansas", "KS");
            mStateMap.put("Kentucky", "KY");
            mStateMap.put("Louisiana", "LA");
            mStateMap.put("Maine", "ME");
            mStateMap.put("Manitoba", "MB");
            mStateMap.put("Maryland", "MD");
            mStateMap.put("Massachusetts", "MA");
            mStateMap.put("Michigan", "MI");
            mStateMap.put("Minnesota", "MN");
            mStateMap.put("Mississippi", "MS");
            mStateMap.put("Missouri", "MO");
            mStateMap.put("Montana", "MT");
            mStateMap.put("Nebraska", "NE");
            mStateMap.put("Nevada", "NV");
            mStateMap.put("New Brunswick", "NB");
            mStateMap.put("New Hampshire", "NH");
            mStateMap.put("New Jersey", "NJ");
            mStateMap.put("New Mexico", "NM");
            mStateMap.put("New York", "NY");
            mStateMap.put("Newfoundland", "NF");
            mStateMap.put("North Carolina", "NC");
            mStateMap.put("North Dakota", "ND");
            mStateMap.put("Northwest Territories", "NT");
            mStateMap.put("Nova Scotia", "NS");
            mStateMap.put("Nunavut", "NU");
            mStateMap.put("Ohio", "OH");
            mStateMap.put("Oklahoma", "OK");
            mStateMap.put("Ontario", "ON");
            mStateMap.put("Oregon", "OR");
            mStateMap.put("Pennsylvania", "PA");
            mStateMap.put("Prince Edward Island", "PE");
            mStateMap.put("Puerto Rico", "PR");
            mStateMap.put("Quebec", "PQ");
            mStateMap.put("Rhode Island", "RI");
            mStateMap.put("Saskatchewan", "SK");
            mStateMap.put("South Carolina", "SC");
            mStateMap.put("South Dakota", "SD");
            mStateMap.put("Tennessee", "TN");
            mStateMap.put("Texas", "TX");
            mStateMap.put("Utah", "UT");
            mStateMap.put("Vermont", "VT");
            mStateMap.put("Virgin Islands", "VI");
            mStateMap.put("Virginia", "VA");
            mStateMap.put("Washington", "WA");
            mStateMap.put("West Virginia", "WV");
            mStateMap.put("Wisconsin", "WI");
            mStateMap.put("Wyoming", "WY");
            mStateMap.put("Yukon Territory", "YT");
        }
    }
}

The regex will match any two letter uppercase word:

(?

The challenge here is "USA" will actually match "US" with a simple two letter upper case search. So we need a lookahead and lookbehind:

?

lookbehind the match

(?

Look behind the match, and make sure there is not an alphanumeric character there (ie, must be a "start of line", whitespace, comma, etc. before the match)

([A-Z]{2})

Match two uppercase letters

?!

lookahead of the match

(?![A-Za-z0-9])

Look ahead of the match, and make sure there is not an alphanumeric character there (ie, must be an "end of line" or whitespace, comma, etc. after the match)