org.apache.hive.hcatalog.data

Class JsonSerDe

java.lang.Object

org.apache.hadoop.hive.serde2.AbstractSerDe

org.apache.hive.hcatalog.data.JsonSerDe

All Implemented Interfaces:

Deserializer, Serializer

public class JsonSerDe
extends AbstractSerDe

Field Summary

Fields inherited from class org.apache.hadoop.hive.serde2.AbstractSerDe

configErrors

Constructor Summary

Constructors

Constructor and Description
JsonSerDe()

Method Summary

Modifier and Type	Method and Description
Object	deserialize(org.apache.hadoop.io.Writable blob) Takes JSON string in Text form, and has to return an object representation above it that's readable by the corresponding object inspector.
String	getHiveInternalColumnName(int fpos)
ObjectInspector	getObjectInspector() Returns an object inspector for the specified schema that is capable of reading in the object representation of the JSON string
int	getPositionFromHiveInternalColumnName(String internalName)
SerDeStats	getSerDeStats() Returns statistics collected when serializing
Class<? extends org.apache.hadoop.io.Writable>	getSerializedClass() Returns the Writable class that would be returned by the serialize method.
void	initialize(org.apache.hadoop.conf.Configuration conf, Properties tbl) Initialize the HiveSerializer.
org.apache.hadoop.io.Writable	serialize(Object obj, ObjectInspector objInspector) Given an object and object inspector pair, traverse the object and generate a Text representation of the object.

Methods inherited from class org.apache.hadoop.hive.serde2.AbstractSerDe

getConfigurationErrors, initialize, shouldStoreFieldsInMetastore

Methods inherited from class java.lang.Object

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

Constructor Detail

JsonSerDe

public JsonSerDe()

Method Detail

initialize

public void initialize(org.apache.hadoop.conf.Configuration conf,
                       Properties tbl)
                throws SerDeException

Description copied from class: AbstractSerDe

Initialize the HiveSerializer.

Specified by:

initialize in interface Deserializer

Specified by:

initialize in interface Serializer

Specified by:

initialize in class AbstractSerDe

Parameters:

conf - System properties. Can be null in compile time

tbl - table properties

Throws:

SerDeException

deserialize

public Object deserialize(org.apache.hadoop.io.Writable blob)
                   throws SerDeException

Takes JSON string in Text form, and has to return an object representation above it that's readable by the corresponding object inspector. For this implementation, since we're using the jackson parser, we can construct our own object implementation, and we use HCatRecord for it

Specified by:

deserialize in interface Deserializer

Specified by:

deserialize in class AbstractSerDe

Parameters:

blob - The Writable object containing a serialized object

Returns:

A Java object representing the contents in the blob.

Throws:

SerDeException

getHiveInternalColumnName

public String getHiveInternalColumnName(int fpos)

getPositionFromHiveInternalColumnName

public int getPositionFromHiveInternalColumnName(String internalName)

serialize

public org.apache.hadoop.io.Writable serialize(Object obj,
                                               ObjectInspector objInspector)
                                        throws SerDeException

Given an object and object inspector pair, traverse the object and generate a Text representation of the object.

Specified by:

serialize in interface Serializer

Specified by:

serialize in class AbstractSerDe

Throws:

SerDeException

getObjectInspector

public ObjectInspector getObjectInspector()
                                   throws SerDeException

Returns an object inspector for the specified schema that is capable of reading in the object representation of the JSON string

Specified by:

getObjectInspector in interface Deserializer

Specified by:

getObjectInspector in class AbstractSerDe

Throws:

SerDeException

getSerializedClass

public Class<? extends org.apache.hadoop.io.Writable> getSerializedClass()

Description copied from class: AbstractSerDe

Returns the Writable class that would be returned by the serialize method. This is used to initialize SequenceFile header.

Specified by:

getSerializedClass in interface Serializer

Specified by:

getSerializedClass in class AbstractSerDe

getSerDeStats

public SerDeStats getSerDeStats()

Description copied from class: AbstractSerDe

Returns statistics collected when serializing

Specified by:

getSerDeStats in interface Deserializer

Specified by:

getSerDeStats in interface Serializer

Specified by:

getSerDeStats in class AbstractSerDe