Package com.fasterxml.jackson.core

Class JsonPointer

  • public class JsonPointer
extends java.lang.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

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static char SEPARATOR
      Character used to separate segments.

    • Field Detail

      • SEPARATOR

        public static final char SEPARATOR
        Character used to separate segments.
        Since:
        2.9
        See Also:
        Constant Field Values

    • Method Detail

      • compile

        public static JsonPointer compile​(java.lang.String input)
                           throws java.lang.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:
        java.lang.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​(java.lang.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 java.lang.String getMatchingProperty()

      • getMatchingIndex

        public int getMatchingIndex()

      • mayMatchProperty

        public boolean mayMatchProperty()
        Returns:
        True if the root selector matches property name (that is, could match field value of JSON Object node)

      • 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​(java.lang.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​(java.lang.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 java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object

      • equals

        public boolean equals​(java.lang.Object o)
        Overrides:
        equals in class java.lang.Object