org.forgerock.json

Class JsonPointer

java.lang.Object

org.forgerock.json.JsonPointer

All Implemented Interfaces:

Iterable<String>

public class JsonPointer
extends Object
implements Iterable<String>

Identifies a specific value within a JSON structure. Conforms with draft-pbryan-zip-json-pointer-02.

Constructor Summary

Constructors

Constructor and Description
JsonPointer() Constructs a JSON pointer, identifying the root value of a JSON structure.
JsonPointer(Iterable<String> iterable) Constructs a JSON pointer from an iterable collection of reference tokens.
JsonPointer(String... tokens) Constructs a JSON pointer from an array of reference tokens.
JsonPointer(String pointer) Constructs a JSON pointer, identifying the specified pointer value.

Method Summary

Modifier and Type	Method and Description
JsonPointer	child(int child) Returns a new JSON pointer, which identifies a specified child element of the array identified by this pointer.
JsonPointer	child(String child) Returns a new JSON pointer, which identifies a specified child member of the object identified by this pointer.
boolean	equals(Object o) Compares the specified object with this pointer for equality.
String	get(int index) Returns the reference token at the specified position.
int	hashCode() Returns the hash code value for this pointer.
boolean	isEmpty() Returns true if this pointer identifies the root value of a JSON structure.
Iterator<String>	iterator() Returns an iterator over the pointer's reference tokens.
String	leaf() Returns the last (leaf) reference token of the JSON pointer, or null if the pointer contains no reference tokens (i.e. references document root).
JsonPointer	parent() Returns a pointer to the parent of the JSON value identified by this JSON pointer, or null if the pointer has no parent JSON value (i.e. references document root).
JsonPointer	relativePointer() Returns a pointer containing all but the first reference token contained in this pointer, or / if this pointer contains less than 2 reference tokens.
JsonPointer	relativePointer(int sz) Returns a pointer containing the last sz reference tokens contained in this pointer.
int	size() Returns the number of reference tokens in the pointer.
String[]	toArray() Returns a newly allocated array of strings, containing the pointer's reference tokens.
String	toString() Returns the JSON pointer string value.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

JsonPointer

public JsonPointer()

Constructs a JSON pointer, identifying the root value of a JSON structure.

JsonPointer

public JsonPointer(String pointer)

Constructs a JSON pointer, identifying the specified pointer value.

Parameters:

pointer - a string containing the JSON pointer of the value to identify.

Throws:

JsonException - if the pointer is malformed.

JsonPointer

public JsonPointer(String... tokens)

Constructs a JSON pointer from an array of reference tokens.

Parameters:

tokens - an array of string reference tokens.

JsonPointer

public JsonPointer(Iterable<String> iterable)

Constructs a JSON pointer from an iterable collection of reference tokens.

Parameters:

iterable - an iterable collection of reference tokens.

Method Detail

size

public int size()

Returns the number of reference tokens in the pointer.

Returns:

the number of reference tokens in the pointer.

get

public String get(int index)

Returns the reference token at the specified position.

Parameters:

index - the index of the reference token to return.

Returns:

the reference token at the specified position.

Throws:

IndexOutOfBoundsException - if the index is out of range.

toArray

public String[] toArray()

Returns a newly allocated array of strings, containing the pointer's reference tokens. No references to the array are maintained by the pointer. Hence, the caller is free to modify it.

Returns:

a newly allocated array of strings, containing the pointer's reference tokens.

parent

public JsonPointer parent()

Returns a pointer to the parent of the JSON value identified by this JSON pointer, or null if the pointer has no parent JSON value (i.e. references document root).

Returns:

a pointer to the parent of of this JSON pointer. Can be null.

relativePointer

public JsonPointer relativePointer()

Returns a pointer containing all but the first reference token contained in this pointer, or / if this pointer contains less than 2 reference tokens.

This method yields the following results:

Input	Output
/	/
/a	/
/a/b	/b
/a/b/c	/b/c

Returns:

A pointer containing all but the first reference token contained in this pointer.

relativePointer

public JsonPointer relativePointer(int sz)

Returns a pointer containing the last sz reference tokens contained in this pointer.

This method yields the following results:

Input	sz	Output
/a/b/c	0	/
/a/b/c	1	/c
/a/b/c	2	/b/c
/a/b/c	3	/a/b/c

Parameters:

sz - The number of trailing reference tokens to retain.

Returns:

A pointer containing the last sz reference tokens contained in this pointer.

Throws:

IndexOutOfBoundsException - If sz is negative or greater than size().

leaf

public String leaf()

Returns the last (leaf) reference token of the JSON pointer, or null if the pointer contains no reference tokens (i.e. references document root).

Returns:

the last (leaf) reference token of the JSON pointer if it exists, null otherwise

child

public JsonPointer child(String child)

Returns a new JSON pointer, which identifies a specified child member of the object identified by this pointer.

Parameters:

child - the name of the child member to identify.

Returns:

the child JSON pointer.

Throws:

NullPointerException - if child is null.

child

public JsonPointer child(int child)

Returns a new JSON pointer, which identifies a specified child element of the array identified by this pointer.

Parameters:

child - the index of the child element to identify.

Returns:

the child JSON pointer.

Throws:

IndexOutOfBoundsException - if child is less than zero.

isEmpty

public boolean isEmpty()

Returns true if this pointer identifies the root value of a JSON structure. More specifically, it returns true if this pointer does not contain any reference tokens (i.e. size() == 0).

Returns:

true if this pointer identifies the root value of a JSON structure.

iterator

public Iterator<String> iterator()

Returns an iterator over the pointer's reference tokens.

Specified by:

iterator in interface Iterable<String>

Returns:

an iterator over the pointer's reference tokens.

toString

public String toString()

Returns the JSON pointer string value.

Overrides:

toString in class Object

Returns:

the JSON pointer string value.

equals

public boolean equals(Object o)

Compares the specified object with this pointer for equality. Returns true if and only if the specified object is also a JSON pointer, both pointers have the same size, and all corresponding pairs of reference tokens in the two pointers are equal.

Overrides:

equals in class Object

Parameters:

o - the object to be compared for equality with this pointer.

Returns:

true if the specified object is equal to this pointer.

hashCode

public int hashCode()

Returns the hash code value for this pointer.

Overrides:

hashCode in class Object

Returns:

the hash code value for this pointer.