Package com.hazelcast.map

Interface MapStore<K,V>

Type Parameters:
K - type of the MapStore key
V - type of the MapStore value
All Superinterfaces:
MapLoader<K,V>
All Known Subinterfaces:
EntryStore<K,V>
All Known Implementing Classes:
GenericMapStore, MapStoreAdapter
public interface MapStore<K,V> extends MapLoader<K,V>
Hazelcast distributed map implementation is an in-memory data store, but it can be backed by any type of data store such as RDBMS, OODBMS, NOSQL, or simply a file-based data store.

IMap.put(key, value) normally stores the entry into JVM's memory. If the MapStore implementation is provided then Hazelcast will also call the MapStore implementation to store the entry into a user-defined storage, such as RDBMS or some other external storage system. It is completely up to the user how the key-value will be stored or deleted.

Same goes for IMap.remove(key).

Store implementation can be called synchronously (write-through) or asynchronously (write-behind) depending on the configuration.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    delete(K key)
    Deletes the entry with a given key from the store.
    void
    deleteAll(Collection<K> keys)
    Deletes multiple entries from the store.
    void
    store(K key, V value)
    Stores the key-value pair.
    void
    storeAll(Map<K,V> map)
    Stores multiple entries.

    Methods inherited from interface com.hazelcast.map.MapLoader

    load, loadAll, loadAllKeys

  • Method Details

    • store

      void store(K key, V value)
      Stores the key-value pair.

      If an exception is thrown then the put operation will fail.

      Parameters:
      key - key of the entry to store
      value - value of the entry to store

    • storeAll

      void storeAll(Map<K,V> map)
      Stores multiple entries.

      Implementation of this method can optimize the store operation by storing all entries in one database connection. storeAll() is used when writeDelaySeconds is positive (write-behind).If an exception is thrown, the entries will try to be stored one by one using the store() method.

      Note: on the retry phase only entries left in the map will be stored one-by-one. In this way a MapStore implementation can handle partial storeAll() cases when some entries were stored successfully before a failure happens. Entries removed from the map will be not passed to subsequent call to store() method anymore.

      Parameters:
      map - map of entries to store

    • delete

      void delete(K key)
      Deletes the entry with a given key from the store.

      If an exception is thrown the remove operation will fail.

      Parameters:
      key - the key to delete from the store

    • deleteAll

      void deleteAll(Collection<K> keys)
      Deletes multiple entries from the store.

      If an exception is thrown the entries will try to be deleted one by one using the delete() method.

      Note: on the retry phase only entries left in the keys will be deleted one-by-one. In this way a MapStore implementation can handle partial deleteAll() cases when some entries were deleted successfully before a failure happens. Entries removed from the keys will be not passed to subsequent call to delete() method anymore. The intended usage is to delete items from the provided collection as they are deleted from the store.

      Parameters:
      keys - the keys of the entries to delete.