JsonPath Expressions

JsonPath expressions always refer to a JSON structure in the same way as XPath expression are used in combination with an XML document. The "root member object" in JsonPath is always referred to as $ regardless if it is an object or array.

JsonPath expressions can use the dot–notation

$.store.book[0].title

or the bracket–notation

$['store']['book'][0]['title']

Operators

 

Operator

Description

$

The root element to query. This starts all path expressions.

@

The current node being processed by a filter predicate.

*

Wildcard. Available anywhere a name or numeric are required.

..

Deep scan. Available anywhere a name is required.

.<name>

Dot-notated child

['<name>' (, '<name>')]

Bracket-notated child or children

[<number> (, <number>)]

Array index or indexes

[start:end]

Array slice operator

[?(<expression>)]

Filter expression. Expression must evaluate to a boolean value.

 

Functions

Functions can be invoked at the tail end of a path - the input to a function is the output of the path expression. The function output is dictated by the function itself.

 

Function

Description

Output

min()

Provides the min value of an array of numbers

Double

max()

Provides the max value of an array of numbers

Double

avg()

Provides the average value of an array of numbers

Double

stddev()

Provides the standard deviation value of an array of numbers

Double

length()

Provides the length of an array Integer

Integer

 

Filter Operators

Filters are logical expressions used to filter arrays. A typical filter would be [?(@.age > 18)] where @ represents the current item being processed. More complex filters can be created with logical operators && and ||. String literals must be enclosed by single or double quotes

 ([?(@.color == 'blue')] or [?(@.color == "blue")])

 

Operator

Description

==

left is equal to right (note that 1 is not equal to '1')

!=

left is not equal to right

left is less than right

<=

left is less or equal to right

left is greater than right

>=

left is greater than or equal to right

=~

left matches regular expression [?(@.name =~ /foo.*?/i)]

in

left exists in right [?(@.size in ['S', 'M'])]

nin

left does not exists in right

subsetof

left is a subset of right [?(@.sizes subsetof ['S', 'M', 'L'])]

size

size of left (array or string) should match right

empty

left (array or string) should be empty

 

Path Examples

{

    "store": {

        "book": [

            {

                "category": "reference",

                "author": "Nigel Rees",

                "title": "Sayings of the Century",

                "price": 8.95

            },

            {

                "category": "fiction",

                "author": "Evelyn Waugh",

                "title": "Sword of Honour",

                "price": 12.99

            },

            {

                "category": "fiction",

                "author": "Herman Melville",

                "title": "Moby Dick",

                "isbn": "0-553-21311-3",

                "price": 8.99

            },

            {

                "category": "fiction",

                "author": "J. R. R. Tolkien",

                "title": "The Lord of the Rings",

                "isbn": "0-395-19395-8",

                "price": 22.99

            }

        ],

        "bicycle": {

            "color": "red",

            "price": 19.95

        }

    },

    "expensive": 10

}