in archaius2-core/src/main/java/com/netflix/archaius/config/AbstractConfig.java [180:191]
public String getString(String key, String defaultValue) {
Object value = getRawProperty(key);
if (value == null) {
return notFound(key, defaultValue != null ? interpolator.create(getLookup()).resolve(defaultValue) : null);
}
if (value instanceof String) {
return resolve((String)value);
} else {
return value.toString();
}
}