org.apache.hadoop.hive.serde2.objectinspector

Class StandardMapObjectInspector

java.lang.Object

org.apache.hadoop.hive.serde2.objectinspector.StandardMapObjectInspector

All Implemented Interfaces:

Cloneable, MapObjectInspector, ObjectInspector, SettableMapObjectInspector

Direct Known Subclasses:

LazyBinaryMapObjectInspector, StandardConstantMapObjectInspector

public class StandardMapObjectInspector
extends Object
implements SettableMapObjectInspector

StandardMapObjectInspector works on map data that is stored as a Java Map object. Note: the key object of the map must support equals and hashCode by itself. We also plan to have a GeneralMapObjectInspector which can work on map with key objects that does not support equals and hashCode. That will require us to store InspectableObject as the key, which will have overridden equals and hashCode methods. Always use the ObjectInspectorFactory to create new ObjectInspector objects, instead of directly creating an instance of this class.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.hadoop.hive.serde2.objectinspector.ObjectInspector

ObjectInspector.Category

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	StandardMapObjectInspector()
protected	StandardMapObjectInspector(ObjectInspector mapKeyObjectInspector, ObjectInspector mapValueObjectInspector) Call ObjectInspectorFactory.getStandardMapObjectInspector instead.

Method Summary

Methods

Modifier and Type	Method and Description
Object	clear(Object map) Clear the map.
Object	create() Create an empty map.
ObjectInspector.Category	getCategory() An ObjectInspector must inherit from one of the following interfaces if getCategory() returns: PRIMITIVE: PrimitiveObjectInspector LIST: ListObjectInspector MAP: MapObjectInspector STRUCT: StructObjectInspector.
Map<?,?>	getMap(Object data) returns null for data = null.
ObjectInspector	getMapKeyObjectInspector()
int	getMapSize(Object data) returns -1 for NULL map.
Object	getMapValueElement(Object data, Object key)
ObjectInspector	getMapValueObjectInspector()
String	getTypeName() Returns the name of the data type that is inspected by this ObjectInspector.
Object	put(Object map, Object key, Object value) Add a key-value pair to the map.
Object	remove(Object map, Object key) Remove a key-value pair from the map.

Methods inherited from class java.lang.Object

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

Constructor Detail

StandardMapObjectInspector

protected StandardMapObjectInspector()

StandardMapObjectInspector

protected StandardMapObjectInspector(ObjectInspector mapKeyObjectInspector,
                          ObjectInspector mapValueObjectInspector)

Call ObjectInspectorFactory.getStandardMapObjectInspector instead.

Method Detail

getMapKeyObjectInspector

public ObjectInspector getMapKeyObjectInspector()

Specified by:

getMapKeyObjectInspector in interface MapObjectInspector

getMapValueObjectInspector

public ObjectInspector getMapValueObjectInspector()

Specified by:

getMapValueObjectInspector in interface MapObjectInspector

getMapValueElement

public Object getMapValueElement(Object data,
                        Object key)

Specified by:

getMapValueElement in interface MapObjectInspector

getMapSize

public int getMapSize(Object data)

Description copied from interface: MapObjectInspector

returns -1 for NULL map.

Specified by:

getMapSize in interface MapObjectInspector

getMap

public Map<?,?> getMap(Object data)

Description copied from interface: MapObjectInspector

returns null for data = null. Note: This method should not return a Map object that is reused by the same MapObjectInspector, because it's possible that the same MapObjectInspector will be used in multiple places in the code. However it's OK if the Map object is part of the Object data.

Specified by:

getMap in interface MapObjectInspector

getCategory

public final ObjectInspector.Category getCategory()

Description copied from interface: ObjectInspector

An ObjectInspector must inherit from one of the following interfaces if getCategory() returns: PRIMITIVE: PrimitiveObjectInspector LIST: ListObjectInspector MAP: MapObjectInspector STRUCT: StructObjectInspector.

Specified by:

getCategory in interface ObjectInspector

getTypeName

public String getTypeName()

Description copied from interface: ObjectInspector

Returns the name of the data type that is inspected by this ObjectInspector. This is used to display the type information to the user. For primitive types, the type name is standardized. For other types, the type name can be something like "list", "map", java class names, or user-defined type names similar to typedef.

Specified by:

getTypeName in interface ObjectInspector

create

public Object create()

Description copied from interface: SettableMapObjectInspector

Create an empty map.

Specified by:

create in interface SettableMapObjectInspector

clear

public Object clear(Object map)

Description copied from interface: SettableMapObjectInspector

Clear the map. Return the map.

Specified by:

clear in interface SettableMapObjectInspector

put

public Object put(Object map,
         Object key,
         Object value)

Description copied from interface: SettableMapObjectInspector

Add a key-value pair to the map. Return the map.

Specified by:

put in interface SettableMapObjectInspector

remove

public Object remove(Object map,
            Object key)

Description copied from interface: SettableMapObjectInspector

Remove a key-value pair from the map. Return the map.

Specified by:

remove in interface SettableMapObjectInspector