org.embulk.spi.json

Class JsonNull

java.lang.Object

org.embulk.spi.json.JsonNull

All Implemented Interfaces:

JsonValue

public final class JsonNull
extends Object
implements JsonValue

Represents null in JSON.

Since:

0.10.42

See Also:

RFC 8259 - The JavaScript Object Notation (JSON) Data Interchange Format

Nested Class Summary

Nested classes/interfaces inherited from interface org.embulk.spi.json.JsonValue

JsonValue.EntityType

Field Summary

Fields

Modifier and Type	Field and Description
static JsonNull	NULL The singleton instance that represents null in JSON.

Method Summary

Modifier and Type	Method and Description
JsonNull	asJsonNull() Returns this value as JsonNull.
boolean	equals(Object otherObject) Compares the specified object with this JSON null for equality.
JsonValue.EntityType	getEntityType() Returns JsonValue.EntityType.NULL, which is the entity type of JsonNull.
int	hashCode() Returns the hash code value for this JSON null.
static JsonNull	of() Returns the singleton instance of JsonNull.
int	presumeReferenceSizeInBytes() Returns 1 for the size of null in bytes presumed to occupy in Page as a reference.
String	toJson() Returns the stringified JSON representation of this JSON null.
Value	toMsgpack() Deprecated. Do not use this method. It is to be removed at some point after Embulk v1.0.0. It is here only to ensure a migration period from MessagePack-based JSON values to new JSON values of JsonValue.
String	toString() Returns the string representation of this JSON null.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.embulk.spi.json.JsonValue

asJsonArray, asJsonBoolean, asJsonDouble, asJsonLong, asJsonObject, asJsonString, fromMsgpack, isJsonArray, isJsonBoolean, isJsonDouble, isJsonLong, isJsonNull, isJsonObject, isJsonString

Field Detail

NULL

public static final JsonNull NULL

The singleton instance that represents null in JSON.

Since:

0.10.42

Method Detail

of

public static JsonNull of()

Returns the singleton instance of JsonNull.

Returns:

the singleton instance of JsonNull

Since:

0.10.42

getEntityType

public JsonValue.EntityType getEntityType()

Returns JsonValue.EntityType.NULL, which is the entity type of JsonNull.

Specified by:

getEntityType in interface JsonValue

Returns:

JsonValue.EntityType.NULL, which is the entity type of JsonNull

Since:

0.10.42

asJsonNull

public JsonNull asJsonNull()

Returns this value as JsonNull.

Specified by:

asJsonNull in interface JsonValue

Returns:

itself as JsonNull

Since:

0.10.42

presumeReferenceSizeInBytes

public int presumeReferenceSizeInBytes()

Returns 1 for the size of null in bytes presumed to occupy in Page as a reference.

This approximate size is used only as a threshold whether PageBuilder is flushed, or not. It is not accurate, it does not need to be accurate, and it is impossible in general to tell an accurate size that a Java object occupies in the Java heap. But, a reasonable approximate would help to keep Page performant in the Java heap.

It is better to flush more frequently for bigger JSON value objects, less often for smaller JSON value objects, but no infinite accumulation even for empty JSON value objects.

Specified by:

presumeReferenceSizeInBytes in interface JsonValue

Returns:

1

See Also:

"org.embulk.spi.PageBuilderImpl#addRecord", SIZE_OF_BYTE in Airlift's Slice

toJson

public String toJson()

Returns the stringified JSON representation of this JSON null.

Specified by:

toJson in interface JsonValue

Returns:

"null"

Since:

0.10.42

toMsgpack

@Deprecated
public Value toMsgpack()

Deprecated. Do not use this method. It is to be removed at some point after Embulk v1.0.0. It is here only to ensure a migration period from MessagePack-based JSON values to new JSON values of JsonValue.

Returns the corresponding MessagePack's Nil value of this JSON null.

Specified by:

toMsgpack in interface JsonValue

Returns:

the corresponding MessagePack's Nil value of this JSON null

Since:

0.10.42

See Also:

Draft EEP: JSON Column Type

toString

public String toString()

Returns the string representation of this JSON null.

Overrides:

toString in class Object

Returns:

"null"

Since:

0.10.42

equals

public boolean equals(Object otherObject)

Compares the specified object with this JSON null for equality.

Overrides:

equals in class Object

Returns:

true if the specified object is equal to this JSON null.

Since:

0.10.42

hashCode

public int hashCode()

Returns the hash code value for this JSON null.

Overrides:

hashCode in class Object

Returns:

the hash code value for this JSON null

Since:

0.10.42