org.apache.gora.cassandra.store

Class CassandraClient<K,T extends PersistentBase>

java.lang.Object

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

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

Field Summary

Fields

Modifier and Type	Field and Description
static org.slf4j.Logger	LOG

Constructor Summary

Constructors

Constructor and Description
CassandraClient()

Method Summary

Methods

Modifier and Type	Method and Description
void	addColumn(K key, String fieldName, Object value) Insert a field in a column.
void	addGenericArray(K key, String fieldName, org.apache.avro.generic.GenericArray<?> array)
void	addStatefulHashMap(K key, String fieldName, Map<CharSequence,Object> map)
void	addSubColumn(K key, String fieldName, ByteBuffer columnName, Object value) Insert a member in a super column.
void	addSubColumn(K key, String fieldName, Integer columnName, Object value) Adds an subColumn inside the cassandraMapping file when an Integer is serialized
void	addSubColumn(K key, String fieldName, String columnName, Object value) Adds an subColumn inside the cassandraMapping file when a String is serialized
void	checkKeyspace() Check if keyspace already exists.
void	deleteByKey(K key) Deletes an entry based on its key.
void	deleteColumn(K key, String familyName, ByteBuffer columnName) Delete a row within the keyspace.
void	deleteGenericArray(K key, String fieldName)
void	deleteStatefulHashMap(K key, String fieldName)
void	deleteSubColumn(K key, String fieldName) Deletes all subcolumns from a super column.
void	deleteSubColumn(K key, String fieldName, ByteBuffer columnName) Delete a member in a super column.
void	deleteSubColumn(K key, String fieldName, String columnName) Deletes a subColumn
void	dropKeyspace() Drop keyspace.
List<me.prettyprint.hector.api.beans.Row<K,ByteBuffer,ByteBuffer>>	execute(CassandraQuery<K,T> cassandraQuery, String family) Select a family column in the keyspace.
List<me.prettyprint.hector.api.beans.SuperRow<K,String,ByteBuffer,ByteBuffer>>	executeSuper(CassandraQuery<K,T> cassandraQuery, String family)
CassandraMapping	getCassandraMapping() Retrieves the cassandraMapping which holds whatever was mapped from the gora-cassandra-mapping.xml
Map<String,List<String>>	getFamilyMap(Query<K,T> query) Select the families that contain at least one column mapped to a query field.
String	getKeyspaceName() Obtain Schema/Keyspace name
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(Class<K> keyClass, Class<T> persistentClass)
boolean	isSuper(String family) Determines if a column is a superColumn or not.
boolean	keyspaceExists() Check if keyspace already exists.
ByteBuffer	toByteBuffer(Object value) Serialize value to ByteBuffer using GoraSerializerTypeInferer.getSerializer(Object).

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(Class<K> keyClass,
              Class<T> persistentClass)
                throws Exception

Throws:

Exception

keyspaceExists

public boolean keyspaceExists()

Check if keyspace already exists.

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(K key,
             String fieldName,
             Object value)

Insert a field in a column.

Parameters:

key - the row key

fieldName - the field name

value - the field value.

deleteColumn

public void deleteColumn(K key,
                String familyName,
                ByteBuffer columnName)

Delete a row within the keyspace.

Parameters:

key -

fieldName -

columnName -

deleteByKey

public void deleteByKey(K key)

Deletes an entry based on its key.

Parameters:

key -

addSubColumn

public void addSubColumn(K key,
                String fieldName,
                ByteBuffer columnName,
                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

columnName - the column name (the member name, or the index of array)

value - the member value

addSubColumn

public void addSubColumn(K key,
                String fieldName,
                String columnName,
                Object value)

Adds an subColumn inside the cassandraMapping file when a String is serialized

Parameters:

key -

fieldName -

columnName -

value -

addSubColumn

public void addSubColumn(K key,
                String fieldName,
                Integer columnName,
                Object value)

Adds an subColumn inside the cassandraMapping file when an Integer is serialized

Parameters:

key -

fieldName -

columnName -

value -

deleteSubColumn

public void deleteSubColumn(K key,
                   String fieldName,
                   ByteBuffer columnName)

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

Parameters:

key - the row key

fieldName - the field name

columnName - the column name (the member name, or the index of array)

deleteSubColumn

public void deleteSubColumn(K key,
                   String fieldName,
                   String columnName)

Deletes a subColumn

Parameters:

key -

fieldName -

columnName -

deleteSubColumn

public void deleteSubColumn(K key,
                   String fieldName)

Deletes all subcolumns from a super column.

Parameters:

key - the row key.

fieldName - the field name.

deleteGenericArray

public void deleteGenericArray(K key,
                      String fieldName)

addGenericArray

public void addGenericArray(K key,
                   String fieldName,
                   org.apache.avro.generic.GenericArray<?> array)

deleteStatefulHashMap

public void deleteStatefulHashMap(K key,
                         String fieldName)

addStatefulHashMap

public void addStatefulHashMap(K key,
                      String fieldName,
                      Map<CharSequence,Object> map)

toByteBuffer

public ByteBuffer toByteBuffer(Object value)

Serialize value to ByteBuffer using GoraSerializerTypeInferer.getSerializer(Object).

Parameters:

value - the member value Object.

Returns:

ByteBuffer object

execute

public List<me.prettyprint.hector.api.beans.Row<K,ByteBuffer,ByteBuffer>> 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.

getCassandraMapping

public CassandraMapping getCassandraMapping()

Retrieves the cassandraMapping which holds whatever was mapped from the gora-cassandra-mapping.xml

Returns:

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)

Determines if a column is a superColumn or not.

Parameters:

family -

Returns:

boolean

executeSuper

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

getKeyspaceName

public String getKeyspaceName()

Obtain Schema/Keyspace name

Returns:

Keyspace