org.neo4j.graphdb.index
Interface Index<T extends PropertyContainer>

Type Parameters:
T - The type of entities this index manages. It may be either Nodes or Relationships.
All Known Subinterfaces:
RelationshipIndex

public interface Index<T extends PropertyContainer>

An index to associate key/value pairs with entities (Nodes or Relationships) for fast lookup and querying. Any number of key/value pairs can be associated with any number of entities using add(PropertyContainer, String, Object) and dissociated with remove(PropertyContainer, String, Object). Querting is done using get(String, Object) for exact lookups and query(Object) or query(String, Object) for more advanced querying, exposing querying capabilities from the backend which is backing this particular index. Write operations participates in transactions so committing and rolling back works the same way as usual in Neo4j.

Author:
Mattias Persson

Method Summary
 void add(T entity, String key, Object value)
          Adds a key/value pair for entity to the index.
 void delete()
          Clears the index and deletes the configuration associated with it.
 IndexHits<T> get(String key, Object value)
          Returns exact matches from this index, given the key/value pair.
 IndexHits<T> query(Object queryOrQueryObject)
          Returns matches from this index based on the supplied query object, which can be a query string or an implementation-specific query object.
 IndexHits<T> query(String key, Object queryOrQueryObject)
          Returns matches from this index based on the supplied key and query object, which can be a query string or an implementation-specific query object.
 void remove(T entity, String key, Object value)
          Removes a key/value pair for entity from the index.
 

Method Detail

add

void add(T entity,
         String key,
         Object value)
Adds a key/value pair for entity to the index. If that key/value pair for the entity is already in the index it's up to the implementation to make it so that such an operation is idempotent.

Parameters:
entity - the entity (i.e Node or Relationship) to associate the key/value pair with.
key - the key in the key/value pair to associate with the entity.
value - the value in the key/value pair to associate with the entity.

remove

void remove(T entity,
            String key,
            Object value)
Removes a key/value pair for entity from the index. If that key/value pair isn't associated with entity in this index this operation doesn't do anything.

Parameters:
entity - the entity (i.e Node or Relationship) to dissociate the key/value pair from.
key - the key in the key/value pair to dissociate from the entity.
value - the value in the key/value pair to dissociate from the entity.

delete

void delete()
Clears the index and deletes the configuration associated with it. After this it's invalid to call any other method on this index. However if the transaction which the delete operation was called in gets rolled back it again becomes ok to use this index.


get

IndexHits<T> get(String key,
                 Object value)
Returns exact matches from this index, given the key/value pair. Matches will be for key/value pairs just as they were added by the add(PropertyContainer, String, Object) method.

Parameters:
key - the key in the key/value pair to match.
value - the value in the key/value pair to match.
Returns:
the result wrapped in an IndexHits object. If the entire result set isn't looped through, IndexHits.close() must be called before disposing of the result.

query

IndexHits<T> query(String key,
                   Object queryOrQueryObject)
Returns matches from this index based on the supplied key and query object, which can be a query string or an implementation-specific query object.

Parameters:
key - the key in this query.
queryOrQueryObject - the query for the key to match.
Returns:
the result wrapped in an IndexHits object. If the entire result set isn't looped through, IndexHits.close() must be called before disposing of the result.

query

IndexHits<T> query(Object queryOrQueryObject)
Returns matches from this index based on the supplied query object, which can be a query string or an implementation-specific query object.

Parameters:
queryOrQueryObject - the query to match.
Returns:
the result wrapped in an IndexHits object. If the entire result set isn't looped through, IndexHits.close() must be called before disposing of the result.


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