Using locale settings to detect wheter to use imperial units

Just give the user the option to choose a preferred unit in a settings menu. If it is a traveling user you don't want the app to be geographically aware, IMO.

In the end I went for the following solution.

public class UnitLocale {
    public static UnitLocale Imperial = new UnitLocale();
    public static UnitLocale Metric = new UnitLocale();

    public static UnitLocale getDefault() {
            return getFrom(Locale.getDefault());
    }
    public static UnitLocale getFrom(Locale locale) {
        String countryCode = locale.getCountry();
        if ("US".equals(countryCode)) return Imperial; // USA
        if ("LR".equals(countryCode)) return Imperial; // liberia
        if ("MM".equals(countryCode)) return Imperial; // burma
        return Metric;
    }
}

Use it like this for example.

if (UnitLocale.getDefault() == UnitLocale.Imperial) convertToimperial();

If convert methods are also need they can preferably be added to subclasses of UnitLocale. I only needed to detect wheter to use imperial units and send it to the server.

Using ints over java objects have extremely slim performance gains and makes the code harder to read. Comparing two references in java is comparable in speed to comparing two ints. Also using objects allow us to add methods to the UnitLocale class or subclasses such as, convertToMetric, etc.