com.hp.util.persistence.cassandra

Class CassAbstractDao<I extends Serializable,K extends Serializable & Comparable<K>,T extends TransportObject<? super T,I>,P extends Storable<I>,F,S>

java.lang.Object

com.hp.util.persistence.cassandra.AbstractBaseDao<I,K,P,F,S>

com.hp.util.persistence.cassandra.CassAbstractDao<I,K,T,P,F,S>

Type Parameters:

I - type of the persistent object and transport object id. This type should be immutable. It is critical this type implements equals() and hashCode() correctly.

K - Type of Column Name.

T - Type of Transportable object

P - type of the persistent/Storable object.

F - type of the associated filter.

S - type of the associated sort specification type.

All Implemented Interfaces:

Converter<P,T>, BaseDao<I,P,F,S,DataStoreContext>, Dao<I,T,P,F,S,DataStoreContext>

public abstract class CassAbstractDao<I extends Serializable,K extends Serializable & Comparable<K>,T extends TransportObject<? super T,I>,P extends Storable<I>,F,S>
extends AbstractBaseDao<I,K,P,F,S>
implements Dao<I,T,P,F,S,DataStoreContext>

The Cassandra specific abstract implementation for Dao. This implementation provides methods for create, update and delete persistence objects in the database

Author:

nachiket

Field Summary

Fields

Modifier and Type	Field and Description
protected List<CfQueryOperations<I,T>>	cfList

Fields inherited from class com.hp.util.persistence.cassandra.AbstractBaseDao

columnDecoderProvider

Constructor Summary

Constructors

Constructor and Description
CassAbstractDao()

Method Summary

Modifier and Type	Method and Description
protected abstract T	conform(T oldTransport, T newTransport)
P	create(T transportable, DataStoreContext context) Creates a new persistent object with the data from the given transport object.
protected abstract P	createStorableInstance(T transportable)
long	delete(F filter, DataStoreContext context) Deletes all persistent objects matching the given filter.
<E extends T> Boolean	delete(Id<E,I> id, DataStoreContext context) Deletes the persistent object with the given id.
long	deleteAll(DataStoreContext context) Deletes all the persistent objects.
P	update(T transportable, DataStoreContext context) This method is used to update existing column values.

Methods inherited from class com.hp.util.persistence.cassandra.AbstractBaseDao

compareRows, count, countByFilter, find, find, findAll, findPagedRows, findRows, get, getColumnDecoder, getColumnFamilyDefinitions, getCountCf, getCountRowKey, getMainColumnFamily

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.hp.util.persistence.BaseDao

count, find, find, findAll, get

Methods inherited from interface com.hp.util.Converter

convert

Field Detail

cfList

protected List<CfQueryOperations<I extends Serializable,T extends TransportObject<? super T,I>>> cfList

Constructor Detail

CassAbstractDao

public CassAbstractDao()
                throws PersistenceConnException

Throws:

PersistenceConnException

Method Detail

create

public P create(T transportable,
                DataStoreContext context)
         throws Exception

Creates a new persistent object with the data from the given transport object.

Specified by:

create in interface Dao<I extends Serializable,T extends TransportObject<? super T,I>,P extends Storable<I>,F,S,DataStoreContext>

Parameters:

transportable - transport object to get the data from.

context - data store context.

Returns:

the new created persistent object.

Throws:

Exception - in case of error in persist data to database.

update

public P update(T transportable,
                DataStoreContext context)
         throws Exception

This method is used to update existing column values. All indexes are also updated. We use Read-Modify-Write to do this. Without Read-Modify-Write, a new index can be added but the older index remains as residue which will create undesired effects TODO: Update without Read-Modify-Write

Specified by:

update in interface Dao<I extends Serializable,T extends TransportObject<? super T,I>,P extends Storable<I>,F,S,DataStoreContext>

Parameters:

transportable - transport object to get the data from.

context - data store context.

Returns:

the updated persistent object.

Throws:

Exception - in case error occurs while updating the data.

delete

public <E extends T> Boolean delete(Id<E,I> id,
                                    DataStoreContext context)
                             throws Exception

Description copied from interface: Dao

Deletes the persistent object with the given id.

Specified by:

delete in interface Dao<I extends Serializable,T extends TransportObject<? super T,I>,P extends Storable<I>,F,S,DataStoreContext>

Parameters:

id - persistent object's id.

context - data store context.

Returns:

true if the persistent object was found and deleted, false if it was not found.

Throws:

Exception - throws if delete fails to operate.

delete

public long delete(F filter,
                   DataStoreContext context)
            throws Exception

Description copied from interface: Dao

Deletes all persistent objects matching the given filter.

Specified by:

delete in interface Dao<I extends Serializable,T extends TransportObject<? super T,I>,P extends Storable<I>,F,S,DataStoreContext>

Parameters:

filter - filter.

context - data store context.

Returns:

number of deleted objects.

Throws:

Exception - throws if delete fails to operate.

deleteAll

public long deleteAll(DataStoreContext context)
               throws Exception

Description copied from interface: Dao

Deletes all the persistent objects.

Specified by:

deleteAll in interface Dao<I extends Serializable,T extends TransportObject<? super T,I>,P extends Storable<I>,F,S,DataStoreContext>

Parameters:

context - data store context

Returns:

the count of entries deleted

Throws:

Exception - throws if delete fails to operate.

createStorableInstance

protected abstract P createStorableInstance(T transportable)

conform

protected abstract T conform(T oldTransport,
                             T newTransport)