oracle.kv.hadoop.hive.table

Class TableSerDe

java.lang.Object

oracle.kv.hadoop.hive.table.TableSerDe

All Implemented Interfaces:

Deserializer, SerDe, Serializer

public class TableSerDe
extends Object

Concrete implementation of TableSerDeBase that performs deserialization and/or serialization of data loaded into a KVStore via the PrimaryKey based Table API.

Field Summary

Fields

Modifier and Type	Field and Description
protected List<Object>	hiveRow
protected MapWritable	kvMapWritable

Constructor Summary

Constructors

Constructor and Description
TableSerDe()

Method Summary

Methods

Modifier and Type	Method and Description
protected ObjectInspector	createObjectInspector()
Object	deserialize(Writable field) Deserializes the given Writable parameter and returns a Java Object representing the contents of that parameter.
ObjectInspector	getObjectInspector() Returns the ObjectInspector that can be used to navigate through the internal structure of the Object returned from the deserialize method.
SerDeStats	getSerDeStats() Returns statistics collected when deserializing and/or serializing.
Class<? extends Writable>	getSerializedClass() Return the Writable class returned by the serialize method; which is used to initialize the SequenceFile header.
void	initialize(Configuration job, Properties tbl)
Writable	serialize(Object obj, ObjectInspector objectInspector) Serialize the given Object by navigating inside the Object with the given ObjectInspector.
String	toString()
protected void	validateParams(Properties tbl) Verifies that the names and types of the fields in the KV Store table correctly map to the names and types of the Hive table against which the Hive query is to be executed.

Methods inherited from class java.lang.Object

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

Field Detail

hiveRow

protected List<Object> hiveRow

kvMapWritable

protected MapWritable kvMapWritable

Constructor Detail

TableSerDe

public TableSerDe()

Method Detail

validateParams

protected void validateParams(Properties tbl)
                       throws SerDeException

Verifies that the names and types of the fields in the KV Store table correctly map to the names and types of the Hive table against which the Hive query is to be executed. Note that this method assumes that both the KVStore parameters and the serde parameters have been initialized. If a mismatch is found between KV Store fields and Hive columns, then a SerDeException will be thrown with a descriptive message.

Throws:

SerDeException

createObjectInspector

protected ObjectInspector createObjectInspector()
                                         throws SerDeException

Throws:

SerDeException

deserialize

public Object deserialize(Writable field)
                   throws SerDeException

Deserializes the given Writable parameter and returns a Java Object representing the contents of that parameter. The field parameter of this method references a field from a row of the KVStore table having the name specified by the tableName field of this class. Thus, the Object returned by this method references the contents of that table field.

Specified by:

deserialize in interface Deserializer

Parameters:

field - The Writable object containing a serialized object from a row of the KVStore table with name specified by tableName.

Returns:

A Java object representing the contents in the given table field parameter.

Throws:

SerDeException

serialize

public Writable serialize(Object obj,
                 ObjectInspector objectInspector)
                   throws SerDeException

Serialize the given Object by navigating inside the Object with the given ObjectInspector. The given Object references a Hive row and the return value is an instance of Writable that references a KVStore table fieldName:fieldValue pair.

Specified by:

serialize in interface Serializer

Parameters:

obj - The Object whose contents are examined and from which the return value is constructed.

objectInspector - The object to use to navigate the given Object's contents.

Returns:

A Writable object representing the contents in the given Object to seriaize.

Throws:

SerDeException

initialize

public void initialize(Configuration job,
              Properties tbl)
                throws SerDeException

Specified by:

initialize in interface Deserializer

Specified by:

initialize in interface Serializer

Throws:

SerDeException

getSerDeStats

public SerDeStats getSerDeStats()

Returns statistics collected when deserializing and/or serializing.

Specified by:

getSerDeStats in interface Deserializer

Specified by:

getSerDeStats in interface Serializer

getObjectInspector

public ObjectInspector getObjectInspector()
                                   throws SerDeException

Returns the ObjectInspector that can be used to navigate through the internal structure of the Object returned from the deserialize method.

Specified by:

getObjectInspector in interface Deserializer

Throws:

SerDeException

getSerializedClass

public Class<? extends Writable> getSerializedClass()

Return the Writable class returned by the serialize method; which is used to initialize the SequenceFile header.

Specified by:

getSerializedClass in interface Serializer

toString

public String toString()

Overrides:

toString in class Object