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

org.codehaus.jackson.node

## Class MissingNode

- java.lang.Object
- - org.codehaus.jackson.JsonNode
  - - org.codehaus.jackson.node.BaseJsonNode
    - - org.codehaus.jackson.node.MissingNode

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

      public final class MissingNode
      extends BaseJsonNode

  This singleton node class is generated to denote "missing nodes" along paths that do not exist. For example, if a path via element of an array is requested for an element outside range of elements in the array; or for a non-array value, result will be reference to this node.

  In most respects this placeholder node will act as `NullNode`; for example, for purposes of value conversions, value is considered to be null and represented as value zero when used for numeric conversions.

- - ### Field Summary

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

      `NO_NODES, NO_STRINGS`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `boolean` | `asBoolean(boolean defaultValue)` Method that will try to convert value of this node to a Java boolean.
    `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 MissingNode` | `getInstance()`
    `boolean` | `isMissingNode()` Method that returns true for "virtual" nodes which represent missing entries constructed by path accessor methods when there is no actual node matching given criteria.
    `JsonNode` | `path(int index)` This method is similar to `JsonNode.get(int)`, except that instead of returning null if no such element exists (due to index being out of range, or this node not being an array), a "missing node" (node that returns true for `JsonNode.isMissingNode()`) will be returned.
    `JsonNode` | `path(String fieldName)` This method is similar to `JsonNode.get(String)`, except that instead of returning null if no such value exists (due to this node not being an object, or object not having value for the specified field), a "missing node" (node that returns true for `JsonNode.isMissingNode()`) will be returned.
    `void` | `serialize(JsonGenerator jg, SerializerProvider provider)` Method called to serialize node instances using given generator.
    `void` | `serializeWithType(JsonGenerator jg, SerializerProvider provider, TypeSerializer typeSer)` Type information is needed, even if JsonNode instances are "plain" JSON, since they may be mixed with other types.
    `String` | `toString()` Note: marked as abstract to ensure all implementation classes define it properly.

    - ### 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, 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, isNull, isNumber, isObject, isPojo, isTextual, isValueNode, iterator, size, with`

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

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

- - ### Method Detail

    - #### getInstance

          public static MissingNode 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 `BaseJsonNode`

    - #### isMissingNode

          public boolean isMissingNode()

      Description copied from class: `JsonNode`
      Method that returns true for "virtual" nodes which represent missing entries constructed by path accessor methods when there is no actual node matching given criteria.

      Note: one and only one of methods `JsonNode.isValueNode()`, `JsonNode.isContainerNode()` and `JsonNode.isMissingNode()` ever returns true for any given node.

      Overrides:
        `isMissingNode` 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`

    - #### asBoolean

          public boolean asBoolean(boolean defaultValue)

      Description copied from class: `JsonNode`
      Method that will try to convert value of this node to a Java boolean. JSON booleans map naturally; integer numbers other than 0 map to true, and 0 maps to false and Strings 'true' and 'false' map to corresponding values.

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

      Overrides:
        `asBoolean` 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`

    - #### path

          public JsonNode path(String fieldName)

      Description copied from class: `JsonNode`
      This method is similar to `JsonNode.get(String)`, except that instead of returning null if no such value exists (due to this node not being an object, or object not having value for the specified field), a "missing node" (node that returns true for `JsonNode.isMissingNode()`) will be returned. This allows for convenient and safe chained access via path calls.
      Specified by:
        `path` in class `JsonNode`

    - #### path

          public JsonNode path(int index)

      Description copied from class: `JsonNode`
      This method is similar to `JsonNode.get(int)`, except that instead of returning null if no such element exists (due to index being out of range, or this node not being an array), a "missing node" (node that returns true for `JsonNode.isMissingNode()`) will be returned. This allows for convenient and safe chained access via path calls.
      Specified by:
        `path` 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`

    - #### serializeWithType

          public void serializeWithType(JsonGenerator jg,
                               SerializerProvider provider,
                               TypeSerializer typeSer)
                                 throws IOException,
                                        JsonProcessingException

      Description copied from class: `BaseJsonNode`
      Type information is needed, even if JsonNode instances are "plain" JSON, since they may be mixed with other types.
      Specified by:
        `serializeWithType` in interface `JsonSerializableWithType`
      Specified by:
        `serializeWithType` 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`

    - #### toString

          public String toString()

      Description copied from class: `JsonNode`

      Note: marked as abstract to ensure all implementation classes define it properly.

      Specified by:
        `toString` in class `JsonNode`