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org.apache.gora.cassandra.store
Class CassandraClient<K,T extends Persistent>

java.lang.Object
  org.apache.gora.cassandra.store.CassandraClient<K,T>

public class CassandraClient<K,T extends Persistent>
extends Object

Field Summary

static org.slf4j.Logger

LOG

Constructor Summary

CassandraClient()

Method Summary

void	addColumn(String key, String fieldName, Object value) Insert a field in a column.
void	addSubColumn(String key, String fieldName, String memberName, Object value) Insert a member in a super column.
void	checkKeyspace() Check if keyspace already exists.
void	dropKeyspace() Drop keyspace.
List<me.prettyprint.hector.api.beans.Row<String,String,String>>	execute(CassandraQuery<K,T> cassandraQuery, String family) Select a family column in the keyspace.
List<me.prettyprint.hector.api.beans.SuperRow<String,String,String,String>>	executeSuper(CassandraQuery<K,T> cassandraQuery, String family)
Map<String,List<String>>	getFamilyMap(Query<K,T> query) Select the families that contain at least one column mapped to a query field.
Map<String,String>	getReverseMap(Query<K,T> query) Select the field names according to the column names, which format if fully qualified: "family:column"
void	initialize()
boolean	isSuper(String family)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOG

public static final org.slf4j.Logger LOG

Constructor Detail

CassandraClient

public CassandraClient()

Method Detail

initialize

public void initialize()
                throws Exception

Throws:

Exception

checkKeyspace

public void checkKeyspace()

Check if keyspace already exists. If not, create it. In this method, we also utilise Hector's logic. It is set by passing a ConfigurableConsistencyLevel object right when the Keyspace is created. Currently consistency level is .ONE which permits consistency to wait until one replica has responded.

dropKeyspace

public void dropKeyspace()

Drop keyspace.

addColumn

public void addColumn(String key,
                      String fieldName,
                      Object value)

Insert a field in a column.

Parameters:

key - the row key

fieldName - the field name

value - the field value.

addSubColumn

public void addSubColumn(String key,
                         String fieldName,
                         String memberName,
                         Object value)

Insert a member in a super column. This is used for map and record Avro types.

Parameters:

key - the row key

fieldName - the field name

memberName - the member name

value - the member value

execute

public List<me.prettyprint.hector.api.beans.Row<String,String,String>> execute(CassandraQuery<K,T> cassandraQuery,
                                                                               String family)

Select a family column in the keyspace.

Parameters:

cassandraQuery - a wrapper of the query

family - the family name to be queried

Returns:

a list of family rows

getFamilyMap

public Map<String,List<String>> getFamilyMap(Query<K,T> query)

Select the families that contain at least one column mapped to a query field.

Parameters:

query - indicates the columns to select

Returns:

a map which keys are the family names and values the corresponding column names required to get all the query fields.

getReverseMap

public Map<String,String> getReverseMap(Query<K,T> query)

Select the field names according to the column names, which format if fully qualified: "family:column"

Parameters:

query -

Returns:

a map which keys are the fully qualified column names and values the query fields

isSuper

public boolean isSuper(String family)

executeSuper

public List<me.prettyprint.hector.api.beans.SuperRow<String,String,String,String>> executeSuper(CassandraQuery<K,T> cassandraQuery,
                                                                                                String family)