NullNode (Jackson JSON Processor)
Date: 2013-07-14

org.codehaus.jackson.node

## Class NullNode

- java.lang.Object
- - org.codehaus.jackson.JsonNode
  - - org.codehaus.jackson.node.BaseJsonNode
    - - org.codehaus.jackson.node.ValueNode
      - - org.codehaus.jackson.node.NullNode

- All Implemented Interfaces:
    Iterable<JsonNode>, JsonSerializable, JsonSerializableWithType

      public final class NullNode
      extends ValueNode

  This singleton value class is used to contain explicit JSON null value.

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static NullNode` | `instance`

    - ### Fields inherited from class org.codehaus.jackson.JsonNode

      `NO_NODES, NO_STRINGS`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `double` | `asDouble(double defaultValue)` Method that will try to convert value of this node to a Java double.
    `int` | `asInt(int defaultValue)` Method that will try to convert value of this node to a Java int.
    `long` | `asLong(long defaultValue)` Method that will try to convert value of this node to a Java long.
    `String` | `asText()` Method that will return valid String representation of the container value, if the node is a value node (method `JsonNode.isValueNode()` returns true), otherwise empty String.
    `JsonToken` | `asToken()` Method that can be used for efficient type detection when using stream abstraction for traversing nodes.
    `boolean` | `equals(Object o)` Equality for node objects is defined as full (deep) value equality.
    `static NullNode` | `getInstance()`
    `boolean` | `isNull()` Method that can be used to check if this node was created from Json liternal null value.
    `void` | `serialize(JsonGenerator jg, SerializerProvider provider)` Method called to serialize node instances using given generator.

    - ### Methods inherited from class org.codehaus.jackson.node.ValueNode

      `isValueNode, path, path, serializeWithType, toString`

    - ### Methods inherited from class org.codehaus.jackson.node.BaseJsonNode

      `findParent, findParents, findPath, findValue, findValues, findValuesAsText, getNumberType, traverse`

    - ### Methods inherited from class org.codehaus.jackson.JsonNode

      `asBoolean, asBoolean, asDouble, asInt, asLong, findParents, findValues, findValuesAsText, get, get, getBigIntegerValue, getBinaryValue, getBooleanValue, getDecimalValue, getDoubleValue, getElements, getFieldNames, getFields, getIntValue, getLongValue, getNumberValue, getPath, getPath, getTextValue, getValueAsBoolean, getValueAsBoolean, getValueAsDouble, getValueAsDouble, getValueAsInt, getValueAsInt, getValueAsLong, getValueAsLong, getValueAsText, has, has, isArray, isBigDecimal, isBigInteger, isBinary, isBoolean, isContainerNode, isDouble, isFloatingPointNumber, isInt, isIntegralNumber, isLong, isMissingNode, isNumber, isObject, isPojo, isTextual, iterator, size, with`

    - ### Methods inherited from class java.lang.Object

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

- - ### Field Detail

    - #### instance

          public static final NullNode instance

  - ### Method Detail

    - #### getInstance

          public static NullNode getInstance()

    - #### asToken

          public JsonToken asToken()

      Description copied from class: `BaseJsonNode`
      Method that can be used for efficient type detection when using stream abstraction for traversing nodes. Will return the first `JsonToken` that equivalent stream event would produce (for most nodes there is just one token but for structured/container types multiple)
      Specified by:
        `asToken` in class `ValueNode`

    - #### isNull

          public boolean isNull()

      Description copied from class: `JsonNode`
      Method that can be used to check if this node was created from Json liternal null value.
      Overrides:
        `isNull` in class `JsonNode`

    - #### asText

          public String asText()

      Description copied from class: `JsonNode`
      Method that will return valid String representation of the container value, if the node is a value node (method `JsonNode.isValueNode()` returns true), otherwise empty String.
      Specified by:
        `asText` in class `JsonNode`

    - #### asInt

          public int asInt(int defaultValue)

      Description copied from class: `JsonNode`
      Method that will try to convert value of this node to a Java int. Numbers are coerced using default Java rules; booleans convert to 0 (false) and 1 (true), and Strings are parsed using default Java language integer parsing rules.

      If representation can not be converted to an int (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.

      Overrides:
        `asInt` in class `JsonNode`

    - #### asLong

          public long asLong(long defaultValue)

      Description copied from class: `JsonNode`
      Method that will try to convert value of this node to a Java long. Numbers are coerced using default Java rules; booleans convert to 0 (false) and 1 (true), and Strings are parsed using default Java language integer parsing rules.

      If representation can not be converted to an long (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.

      Overrides:
        `asLong` in class `JsonNode`

    - #### asDouble

          public double asDouble(double defaultValue)

      Description copied from class: `JsonNode`
      Method that will try to convert value of this node to a Java double. Numbers are coerced using default Java rules; booleans convert to 0.0 (false) and 1.0 (true), and Strings are parsed using default Java language integer parsing rules.

      If representation can not be converted to an int (including structured types like Objects and Arrays), specified defaultValue will be returned; no exceptions are thrown.

      Overrides:
        `asDouble` in class `JsonNode`

    - #### serialize

          public final void serialize(JsonGenerator jg,
                       SerializerProvider provider)
                               throws IOException,
                                      JsonProcessingException

      Description copied from class: `BaseJsonNode`
      Method called to serialize node instances using given generator.
      Specified by:
        `serialize` in interface `JsonSerializable`
      Specified by:
        `serialize` in class `BaseJsonNode`
      Throws:
        `IOException`
        `JsonProcessingException`

    - #### equals

          public boolean equals(Object o)

      Description copied from class: `JsonNode`
      Equality for node objects is defined as full (deep) value equality. This means that it is possible to compare complete JSON trees for equality by comparing equality of root nodes.

      Note: marked as abstract to ensure all implementation classes define it properly and not rely on definition from `Object`.

      Specified by:
        `equals` in class `JsonNode`