de.hpi.fgis.dude.util.data.json
Class JsonNull

java.lang.Object
  de.hpi.fgis.dude.util.data.json.JsonNull

All Implemented Interfaces:

AutoJsonable, JsonAtomic, JsonValue, Jsonable, Comparable<JsonValue>

public class JsonNull
extends Object
implements JsonAtomic

JsonNull represents the Json null value. Parts of the code are reused and were taken from the JSON.org implementation.

Author:

Matthias Pohl

Nested Class Summary

Nested classes/interfaces inherited from interface de.hpi.fgis.dude.util.data.json.JsonValue

JsonValue.JsonType

Field Summary

static JsonNull

NULL The Json null value.

Method Summary

protected Object	clone() There is only intended to be a single instance of the NULL object, so the clone method returns itself.
int	compareTo(JsonValue other) Compares the current instance with the passed JsonValue.
boolean	equals(Object object) A JsonRecord.JsonNull object is equal to the null value and to itself.
void	fromJson(DuDeJsonParser<?> jsonParser) Initializes the current instance using the passed DuDeJsonParser.
String	getStringValue() Returns the actual value converted into a String.
JsonValue.JsonType	getType() Returns JsonType.Null.
int	hashCode()
int	size() Returns 0 since JsonRecord.JsonNull does not have any value.
void	toJson(DuDeJsonGenerator jsonGenerator) Generates the Json code using the passed DuDeJsonGenerator.
String	toString() Returns the "null" String value.

Methods inherited from class java.lang.Object

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

Field Detail

NULL

public static final JsonNull NULL

The Json null value.

Method Detail

clone

protected final Object clone()

There is only intended to be a single instance of the NULL object, so the clone method returns itself.

Overrides:

clone in class Object

Returns:

NULL.

equals

public boolean equals(Object object)

A JsonRecord.JsonNull object is equal to the null value and to itself.

Overrides:

equals in class Object

Parameters:

object - An object to test for being null.

Returns:

true if the object parameter is the JsonRecord.JsonNull object or null; otherwise false.

toString

public String toString()

Returns the "null" String value.

Overrides:

toString in class Object

Returns:

The String "null".

getType

public JsonValue.JsonType getType()

Returns JsonType.Null.

Specified by:

getType in interface JsonValue

Returns:

The type of the current instance.

See Also:

JsonValue.getType()

size

public int size()

Returns 0 since JsonRecord.JsonNull does not have any value.

Specified by:

size in interface JsonValue

Returns:

The number of concrete Java objects that are collected by the current instance.

See Also:

JsonValue.size()

compareTo

public int compareTo(JsonValue other)

Description copied from interface: JsonValue

Compares the current instance with the passed JsonValue. Instances of different JsonValue.JsonTypes are ordered lexicographically except for JsonValue.JsonType.Null. The above mentioned requirements define the following order: null == JsonValue.JsonType.Null < JsonValue.JsonType.Array < JsonValue.JsonType.Boolean < JsonValue.JsonType.Number < JsonValue.JsonType.Record < JsonValue.JsonType.String.

Specified by:

compareTo in interface JsonValue

Specified by:

compareTo in interface Comparable<JsonValue>

See Also:

Comparable.compareTo(Object)

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toJson

public void toJson(DuDeJsonGenerator jsonGenerator)
            throws org.codehaus.jackson.JsonGenerationException,
                   IOException

Description copied from interface: Jsonable

Generates the Json code using the passed DuDeJsonGenerator.

Specified by:

toJson in interface Jsonable

Parameters:

jsonGenerator - The DuDeJsonGenerator that is used internally.

Throws:

org.codehaus.jackson.JsonGenerationException - If an error occurs while generating the Json syntax.

IOException - If an error occurs while writing to the output.

fromJson

public void fromJson(DuDeJsonParser<?> jsonParser)
              throws org.codehaus.jackson.JsonParseException,
                     IOException

Description copied from interface: Jsonable

Initializes the current instance using the passed DuDeJsonParser.

Specified by:

fromJson in interface Jsonable

Parameters:

jsonParser - The parser that is used for extracting the data out of the Json.

Throws:

org.codehaus.jackson.JsonParseException - If an error occurs while parsing the Json.

IOException - If an error occurs while reading from the stream.

getStringValue

public String getStringValue()

Description copied from interface: JsonAtomic

Returns the actual value converted into a String. This method should be preferred in contrast to #toString().

Specified by:

getStringValue in interface JsonAtomic

Returns:

The actual value converted into a String.