com.mmnaseri.utils.spring.data.store

Interface DataStore<K extends Serializable,E>

All Known Subinterfaces:

QueueingDataStore<K,E,B>

All Known Implementing Classes:

EventPublishingDataStore, MemoryDataStore

public interface DataStore<K extends Serializable,E>

This interface encapsulates the abstract data store, with the bare minimum capabilities assumed.

Since:

1.0 (9/17/15)

Author:

Milad Naseri (mmnaseri@programmer.net)

Method Summary

Modifier and Type	Method and Description
boolean	delete(K key) Deletes the entity identifiable with the provided key, or does nothing if no such entity exists.
Class<E>	getEntityType()
boolean	hasKey(K key) Determines whether or not an entity with the given key exists in the data store.
Collection<K>	keys()
E	retrieve(K key) Given a key, retrieves the entity associated with that key in the data store.
Collection<E>	retrieveAll()
boolean	save(K key, E entity) Saves the given entity into the data store under the provided key.
void	truncate() Does a hard remove of all the entities in the data store

Method Detail

hasKey

boolean hasKey(K key)

Determines whether or not an entity with the given key exists in the data store.

Parameters:

key - the key

Returns:

boolean if such a key is known by the data store

save

boolean save(K key,
             E entity)

Saves the given entity into the data store under the provided key. Whether or not the key is actually used by the data store in some sort of mapping does not matter. The only expectation is that after this call, should the save be successful a call to hasKey(Serializable) should yield true and the very same entity (or an equal value entity) can be retrieved by calling retrieve(Serializable).

Parameters:

key - the key

entity - the entity

Returns:

true to indicate the entity was a new entry, and false to indicate another entity had to be replaced/updated with the provided entity

delete

boolean delete(K key)

Deletes the entity identifiable with the provided key, or does nothing if no such entity exists. It is expected that as a side effect, once this method returns successfully, hasKey(Serializable) should return false and retrieve(Serializable) should return null for the same key.

Parameters:

key - the key for which the removal should happen

Returns:

true to indicate the entity was located and removed and false to indicate that no such entity existed in the first place.

retrieve

E retrieve(K key)

Given a key, retrieves the entity associated with that key in the data store.

Parameters:

key - the key

Returns:

the entity or null if no such entity could be found

keys

Collection<K> keys()

Returns:

a collection of all the keys registered in the data store.

retrieveAll

Collection<E> retrieveAll()

Returns:

retrieves all the entities in the data store

getEntityType

Class<E> getEntityType()

Returns:

the entity type bound to this data store

truncate

void truncate()

Does a hard remove of all the entities in the data store