Trovit/src/main/java/org/openestate/io/trovit/TrovitUtils.java
public static String printCountryValue(String value) {
        value = StringUtils.trimToNull(value);
        if (value == null)
            throw new IllegalArgumentException("Can't print empty country value!");
        if (value.length() != 2 && value.length() != 3)
            throw new IllegalArgumentException("Can't print country value '" + value + "' because it is neither an ISO-2-Code nor an ISO-3-Code!");

        return StringUtils.upperCase(value, Locale.ENGLISH);
    }
public static String printCountryValue(String value) {
        value = StringUtils.trimToNull(value);
        if (value == null)
            throw new IllegalArgumentException("Can't print empty country value!");
        if (value.length() != 2 && value.length() != 3)
            throw new IllegalArgumentException("Can't print country value '" + value + "' because it is neither an ISO-2-Code nor an ISO-3-Code!");

        return StringUtils.upperCase(value, Locale.ENGLISH);
    }
Write a {@link String} value for a country code into XML output.
<p>
The country has to be represendet by a ISO-Code wirh two or three
characters.

@param value value to write
@return XML string
@throws IllegalArgumentException if a validation error occurred