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org.apache.gora.store.impl
Class DataStoreBase<K,T extends Persistent>

java.lang.Object
  org.apache.gora.store.impl.DataStoreBase<K,T>

All Implemented Interfaces:

Closeable, DataStore<K,T>, org.apache.hadoop.conf.Configurable, org.apache.hadoop.io.Writable

Direct Known Subclasses:

AccumuloStore, CassandraStore, FileBackedDataStoreBase, HBaseStore, MemStore, SqlStore

public abstract class DataStoreBase<K,T extends Persistent>
extends Object
implements DataStore<K,T>

A Base class for DataStores.

Field Summary

protected boolean	autoCreateSchema
protected BeanFactory<K,T>	beanFactory
protected org.apache.hadoop.conf.Configuration	conf
protected PersistentDatumReader<T>	datumReader
protected PersistentDatumWriter<T>	datumWriter
protected Map<String,org.apache.avro.Schema.Field>	fieldMap A map of field names to Field objects containing schema's fields
protected Class<K>	keyClass
protected Class<T>	persistentClass
protected Properties	properties
protected org.apache.avro.Schema	schema The schema of the persistent class

Constructor Summary

DataStoreBase()

Method Summary

boolean	equals(Object obj)
T	get(K key) Returns the object corresponding to the given key fetching all the fields.
BeanFactory<K,T>	getBeanFactory() Returns the BeanFactory used by the DataStore
org.apache.hadoop.conf.Configuration	getConf()
protected String[]	getFieldsToQuery(String[] fields) Checks whether the fields argument is null, and if so returns all the fields of the Persistent object, else returns the argument.
Class<K>	getKeyClass() Returns the class of the keys
protected org.apache.hadoop.conf.Configuration	getOrCreateConf()
Class<T>	getPersistentClass() Returns the class of the persistent objects
protected String	getSchemaName(String mappingSchemaName, Class<?> persistentClass) Returns the name of the schema to use for the persistent class.
void	initialize(Class<K> keyClass, Class<T> persistentClass, Properties properties) Initializes this DataStore.
K	newKey() Returns a new instance of the key object.
T	newPersistent() Returns a new instance of the managed persistent object.
void	readFields(DataInput in)
void	setBeanFactory(BeanFactory<K,T> beanFactory) Sets the BeanFactory to use by the DataStore.
void	setConf(org.apache.hadoop.conf.Configuration conf)
void	setKeyClass(Class<K> keyClass) Sets the class of the keys
void	setPersistentClass(Class<T> persistentClass) Sets the class of the persistent objects
void	truncateSchema() Deletes all the data associated with the schema, but keeps the schema (table or similar) intact.
void	write(DataOutput out)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.gora.store.DataStore

close, createSchema, delete, deleteByQuery, deleteSchema, execute, flush, get, getPartitions, getSchemaName, newQuery, put, schemaExists

Field Detail

beanFactory

protected BeanFactory<K,T extends Persistent> beanFactory

keyClass

protected Class<K> keyClass

persistentClass

protected Class<T extends Persistent> persistentClass

schema

protected org.apache.avro.Schema schema

The schema of the persistent class

fieldMap

protected Map<String,org.apache.avro.Schema.Field> fieldMap

A map of field names to Field objects containing schema's fields

conf

protected org.apache.hadoop.conf.Configuration conf

autoCreateSchema

protected boolean autoCreateSchema

properties

protected Properties properties

datumReader

protected PersistentDatumReader<T extends Persistent> datumReader

datumWriter

protected PersistentDatumWriter<T extends Persistent> datumWriter

Constructor Detail

DataStoreBase

public DataStoreBase()

Method Detail

initialize

public void initialize(Class<K> keyClass,
                       Class<T> persistentClass,
                       Properties properties)
                throws IOException

Description copied from interface: DataStore

Initializes this DataStore.

Specified by:

initialize in interface DataStore<K,T extends Persistent>

Parameters:

keyClass - the class of the keys

persistentClass - the class of the persistent objects

properties - extra metadata

Throws:

IOException

setPersistentClass

public void setPersistentClass(Class<T> persistentClass)

Description copied from interface: DataStore

Sets the class of the persistent objects

Specified by:

setPersistentClass in interface DataStore<K,T extends Persistent>

Parameters:

persistentClass - class of persistent objects

getPersistentClass

public Class<T> getPersistentClass()

Description copied from interface: DataStore

Returns the class of the persistent objects

Specified by:

getPersistentClass in interface DataStore<K,T extends Persistent>

Returns:

class of the persistent objects

getKeyClass

public Class<K> getKeyClass()

Description copied from interface: DataStore

Returns the class of the keys

Specified by:

getKeyClass in interface DataStore<K,T extends Persistent>

Returns:

class of the keys

setKeyClass

public void setKeyClass(Class<K> keyClass)

Description copied from interface: DataStore

Sets the class of the keys

Specified by:

setKeyClass in interface DataStore<K,T extends Persistent>

Parameters:

keyClass - the class of keys

newKey

public K newKey()
         throws IOException

Description copied from interface: DataStore

Returns a new instance of the key object. If the object cannot be instantiated (it the class is a Java primitive wrapper, or does not have no-arg constructor) it throws an exception. Only use this function if you can make sure that the key class has a no-arg constructor.

Specified by:

newKey in interface DataStore<K,T extends Persistent>

Returns:

a new instance of the key object.

Throws:

IOException

newPersistent

public T newPersistent()
                                   throws IOException

Description copied from interface: DataStore

Returns a new instance of the managed persistent object.

Specified by:

newPersistent in interface DataStore<K,T extends Persistent>

Returns:

a new instance of the managed persistent object.

Throws:

IOException

setBeanFactory

public void setBeanFactory(BeanFactory<K,T> beanFactory)

Description copied from interface: DataStore

Sets the BeanFactory to use by the DataStore.

Specified by:

setBeanFactory in interface DataStore<K,T extends Persistent>

Parameters:

beanFactory - the BeanFactory to use

getBeanFactory

public BeanFactory<K,T> getBeanFactory()

Description copied from interface: DataStore

Returns the BeanFactory used by the DataStore

Specified by:

getBeanFactory in interface DataStore<K,T extends Persistent>

Returns:

the BeanFactory used by the DataStore

get

public T get(K key)
                         throws IOException

Description copied from interface: DataStore

Returns the object corresponding to the given key fetching all the fields.

Specified by:

get in interface DataStore<K,T extends Persistent>

Parameters:

key - the key of the object

Returns:

the Object corresponding to the key or null if it cannot be found

Throws:

IOException

getFieldsToQuery

protected String[] getFieldsToQuery(String[] fields)

Checks whether the fields argument is null, and if so returns all the fields of the Persistent object, else returns the argument.

getConf

public org.apache.hadoop.conf.Configuration getConf()

Specified by:

getConf in interface DataStore<K,T extends Persistent>

Specified by:

getConf in interface org.apache.hadoop.conf.Configurable

setConf

public void setConf(org.apache.hadoop.conf.Configuration conf)

Specified by:

setConf in interface DataStore<K,T extends Persistent>

Specified by:

setConf in interface org.apache.hadoop.conf.Configurable

getOrCreateConf

protected org.apache.hadoop.conf.Configuration getOrCreateConf()

readFields

public void readFields(DataInput in)
                throws IOException

Specified by:

readFields in interface DataStore<K,T extends Persistent>

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

IOException

write

public void write(DataOutput out)
           throws IOException

Specified by:

write in interface DataStore<K,T extends Persistent>

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

IOException

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

truncateSchema

public void truncateSchema()
                    throws IOException

Description copied from interface: DataStore

Deletes all the data associated with the schema, but keeps the schema (table or similar) intact.

Specified by:

truncateSchema in interface DataStore<K,T extends Persistent>

Throws:

IOException

getSchemaName

protected String getSchemaName(String mappingSchemaName,
                               Class<?> persistentClass)

Returns the name of the schema to use for the persistent class. The schema name is prefixed with schema.prefix from Configuration. The schema name in the defined properties is returned. If null then the provided mappingSchemaName is returned. If this is null too, the class name, without the package, of the persistent class is returned.

Parameters:

mappingSchemaName - the name of the schema as read from the mapping file

persistentClass - persistent class