JsonPointer (jackson-core 2.10.0.pr3)

java.lang.Object
- com.fasterxml.jackson.core.JsonPointer

```
public class JsonPointer
extends Object
```
Implementation of JSON Pointer specification. Pointer instances can be used to locate logical JSON nodes for things like tree traversal (see TreeNode.at(com.fasterxml.jackson.core.JsonPointer)). It may be used in future for filtering of streaming JSON content as well (not implemented yet for 2.3).
Instances are fully immutable and can be cached, shared between threads.

Since:

2.3

Author:

Tatu Saloranta

Property Summary

All Methods Instance Methods Concrete Methods
Type Property and Description

boolean mayMatch

All Methods Instance Methods Concrete Methods
Type	Property and Description
`boolean`	`mayMatch`

Field Summary

Fields
Modifier and Type	Field and Description
`protected String`	`_asString` We will retain representation of the pointer, as a String, so that `toString()` should be as efficient as possible.
`protected JsonPointer`	`_head` Reference from currently matching segment (if any) to node before leaf.
`protected int`	`_matchingElementIndex`
`protected String`	`_matchingPropertyName`
`protected JsonPointer`	`_nextSegment` Reference to rest of the pointer beyond currently matching segment (if any); null if this pointer refers to the matching segment.
`protected static JsonPointer`	`EMPTY` Marker instance used to represent segment that matches current node or position (that is, returns true for `matches()`).
`static char`	`SEPARATOR` Character used to separate segments.

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`JsonPointer()` Constructor used for creating "empty" instance, used to represent state that matches current node.
`protected`	`JsonPointer(String fullString, String segment, int matchIndex, JsonPointer next)`
`protected`	`JsonPointer(String fullString, String segment, JsonPointer next)` Constructor used for creating non-empty Segments

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected JsonPointer`	`_constructHead()`
`protected JsonPointer`	`_constructHead(int suffixLength, JsonPointer last)`
`protected static JsonPointer`	`_parseQuotedTail(String input, int i)` Method called to parse tail of pointer path, when a potentially escaped character has been seen.
`protected static JsonPointer`	`_parseTail(String input)`
`JsonPointer`	`append(JsonPointer tail)` Mutant factory method that will return `tail` if `this` instance is "empty" pointer, OR `this` instance if `tail` is "empty" pointer, OR Newly constructed `JsonPointer` instance that starts with all segments of `this`, followed by all segments of `tail`.
`static JsonPointer`	`compile(String input)` Factory method that parses given input and construct matching pointer instance, if it represents a valid JSON Pointer: if not, a `IllegalArgumentException` is thrown.
`static JsonPointer`	`empty()` Accessor for an "empty" expression, that is, one you can get by calling `compile(java.lang.String)` with "" (empty String).
`boolean`	`equals(Object o)`
`static JsonPointer`	`forPath(JsonStreamContext context, boolean includeRoot)` Factory method that will construct a pointer instance that describes path to location given `JsonStreamContext` points to.
`int`	`getMatchingIndex()`
`String`	`getMatchingProperty()`
`int`	`hashCode()`
`JsonPointer`	`head()` Accessor for getting a pointer instance that is identical to this instance except that the last segment has been dropped.
`JsonPointer`	`last()` Returns the leaf of current JSON Pointer expression.
`JsonPointer`	`matchElement(int index)`
`boolean`	`matches()`
`boolean`	`matchesElement(int index)` Method that may be called to see if the pointer would match array element (of a JSON Array) with given index.
`boolean`	`matchesProperty(String name)` Method that may be called to see if the pointer would match property (of a JSON Object) with given name.
`JsonPointer`	`matchProperty(String name)`
`boolean`	`mayMatchElement()`
`boolean`	`mayMatchProperty()`
`JsonPointer`	`tail()` Accessor for getting a "sub-pointer", instance where current segment has been removed and pointer includes rest of segments.
`String`	`toString()`
`static JsonPointer`	`valueOf(String input)` Alias for `compile(java.lang.String)`; added to make instances automatically deserializable by Jackson databind.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Property Detail
  - mayMatch
```
public boolean mayMatchProperty
```
- Field Detail
  - SEPARATOR
```
public static final char SEPARATOR
```
    Character used to separate segments.
    
    Since:
    
    2.9
    
    See Also:
    
    Constant Field Values
  - EMPTY
```
protected static final JsonPointer EMPTY
```
    Marker instance used to represent segment that matches current node or position (that is, returns true for matches()).
  - _nextSegment
```
protected final JsonPointer _nextSegment
```
    Reference to rest of the pointer beyond currently matching segment (if any); null if this pointer refers to the matching segment.
  - _head
```
protected volatile JsonPointer _head
```
    Reference from currently matching segment (if any) to node before leaf. Lazily constructed if/as needed.
    NOTE: we'll use `volatile` here assuming that this is unlikely to become a performance bottleneck. If it becomes one we can probably just drop it and things still should work (despite warnings as per JMM regarding visibility (and lack thereof) of unguarded changes).
    
    Since:
    
    2.5
  - _asString
```
protected final String _asString
```
    We will retain representation of the pointer, as a String, so that toString() should be as efficient as possible.
  - _matchingPropertyName
```
protected final String _matchingPropertyName
```
  - _matchingElementIndex
```
protected final int _matchingElementIndex
```
- Constructor Detail
  - JsonPointer
```
protected JsonPointer()
```
    Constructor used for creating "empty" instance, used to represent state that matches current node.
  - JsonPointer
```
protected JsonPointer(String fullString,
                      String segment,
                      JsonPointer next)
```
    Constructor used for creating non-empty Segments
  - JsonPointer
```
protected JsonPointer(String fullString,
                      String segment,
                      int matchIndex,
                      JsonPointer next)
```
    Since:
    
    2.5
- Method Detail
  - compile
```
public static JsonPointer compile(String input)
                           throws IllegalArgumentException
```
    Factory method that parses given input and construct matching pointer instance, if it represents a valid JSON Pointer: if not, a IllegalArgumentException is thrown.
    
    Throws:
    
    IllegalArgumentException - Thrown if the input does not present a valid JSON Pointer expression: currently the only such expression is one that does NOT start with a slash ('/').
  - valueOf
```
public static JsonPointer valueOf(String input)
```
    Alias for compile(java.lang.String); added to make instances automatically deserializable by Jackson databind.
  - empty
```
public static JsonPointer empty()
```
    Accessor for an "empty" expression, that is, one you can get by calling compile(java.lang.String) with "" (empty String).
    NOTE: this is different from expression for "/" which would instead match Object node property with empty String ("") as name.
    
    Since:
    
    2.10
  - forPath
```
public static JsonPointer forPath(JsonStreamContext context,
                                  boolean includeRoot)
```
    Factory method that will construct a pointer instance that describes path to location given JsonStreamContext points to.
    
    Parameters:
    
    context - Context to build pointer expression fot
    
    includeRoot - Whether to include number offset for virtual "root context" or not.
    
    Since:
    
    2.9
  - matches
```
public boolean matches()
```
  - getMatchingProperty
```
public String getMatchingProperty()
```
  - getMatchingIndex
```
public int getMatchingIndex()
```
  - mayMatchProperty
```
public boolean mayMatchProperty()
```
  - mayMatchElement
```
public boolean mayMatchElement()
```
    Returns:
    
    True if the root selector matches element index (that is, could match an element of JSON Array node)
  - last
```
public JsonPointer last()
```
    Returns the leaf of current JSON Pointer expression. Leaf is the last non-null segment of current JSON Pointer.
    
    Since:
    
    2.5
  - append
```
public JsonPointer append(JsonPointer tail)
```
    Mutant factory method that will return
    - `tail` if `this` instance is "empty" pointer, OR
    - `this` instance if `tail` is "empty" pointer, OR
    - Newly constructed JsonPointer instance that starts with all segments of `this`, followed by all segments of `tail`.
    Parameters:
    
    tail - JsonPointer instance to append to this one, to create a new pointer instance
    
    Returns:
    
    Either `this` instance, `tail`, or a newly created combination, as per description above.
  - matchesProperty
```
public boolean matchesProperty(String name)
```
    Method that may be called to see if the pointer would match property (of a JSON Object) with given name.
    
    Since:
    
    2.5
  - matchProperty
```
public JsonPointer matchProperty(String name)
```
  - matchesElement
```
public boolean matchesElement(int index)
```
    Method that may be called to see if the pointer would match array element (of a JSON Array) with given index.
    
    Since:
    
    2.5
  - matchElement
```
public JsonPointer matchElement(int index)
```
    Since:
    
    2.6
  - tail
```
public JsonPointer tail()
```
    Accessor for getting a "sub-pointer", instance where current segment has been removed and pointer includes rest of segments. For matching state, will return null.
  - head
```
public JsonPointer head()
```
    Accessor for getting a pointer instance that is identical to this instance except that the last segment has been dropped. For example, for JSON Point "/root/branch/leaf", this method would return pointer "/root/branch" (compared to tail() that would return "/branch/leaf"). For leaf
    
    Since:
    
    2.5
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - equals
```
public boolean equals(Object o)
```
    Overrides:
    
    equals in class Object
  - _parseTail
```
protected static JsonPointer _parseTail(String input)
```
  - _parseQuotedTail
```
protected static JsonPointer _parseQuotedTail(String input,
                                              int i)
```
    Method called to parse tail of pointer path, when a potentially escaped character has been seen.
    
    Parameters:
    
    input - Full input for the tail being parsed
    
    i - Offset to character after tilde
  - _constructHead
```
protected JsonPointer _constructHead()
```
  - _constructHead
```
protected JsonPointer _constructHead(int suffixLength,
                                     JsonPointer last)
```

Class JsonPointer

Property Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Property Detail

mayMatch

Field Detail

SEPARATOR

EMPTY

_nextSegment

_head

_asString

_matchingPropertyName

_matchingElementIndex

Constructor Detail

JsonPointer

JsonPointer

JsonPointer

Method Detail

compile

valueOf

empty

forPath

matches

getMatchingProperty

getMatchingIndex

mayMatchProperty

mayMatchElement

last

append

matchesProperty

matchProperty

matchesElement

matchElement

tail

head

toString

hashCode

equals

_parseTail

_parseQuotedTail

_constructHead

_constructHead