| Interface | Description | 
|---|---|
| AddressValidator | 
 Object that implement this interface know how to validate an address
 of type atg.core.util.Address or any of its subclasses. 
 | 
| Class | Description | 
|---|---|
| AddressValidatorImpl | 
 This class provides a default implementation of AddressValidator. 
 | 
| ConcurrentUpdateDetector | 
 This class is intended to detect concurrent update attemps by checking
 exceptions to see if they are, or contain, ConcurrentUpdateExceptions (CUE) or
 InvalidVersionExceptions (IVE). 
 | 
| ContextValueRetriever | 
 Determines the appropriate value for a profile property based on a site,
 and possibly what is already in the profile. 
 | 
| MapToArrayDefaultFirst | 
 
 This droplet is used to convert a map of items to a sorted array of map entries
 with the default item in the beginning of the array. 
 | 
| PlaceList | 
 This class represents a list of places, each of which has a code and an
 associated display name. 
 | 
| RepeatingRequestMonitor | 
 The class RepeatingRequestMonitor is designed for use as a session scoped
 component. | 
| TransactionLockFactory | 
 The transaction lock factory is used to grab locks before beginning and ending
 a transaction. 
 | 
| TransactionLockService | 
 This class is used to acquire and release locks that are used before and after creating new transactions. 
 |