[Solved] Found out the number of Address Component Needed for A country

Country Codes under new Devnet resources:

https://devnet.onenetwork.com/oms/apps/DeveloperNetwork/www/docs/api/javadoc/com/onenetwork/platform/common/address/CountryCodes.html

On the server (using private APIs):

AddressStructureHelper addrStructHelper = AddressConfigCacheManager.getAddressStructureHelper(CountryCodes.fromValue("US"));
AddressStructure addrStructure = addrStructHelper.getAddressStructure();

The resulting AddressStructure is a JAXB object that corresponds to the element in server/cfg/address/META-INF/AddressConfig.xml.

On the client:

You can use One.AddressStructureCache.getAddressStructure() to fetch the same structure in Javascript. The class is marked private in the documentation but the API is old and unlikely to change. If you're trying to access this information on the client, let me know and I can improve the documentation.