JsonPath 语法 与 XPath 对比
JsonPath 语法 与 XPath 对比
XPath | JSONPath | Description |
/ | $ | the root object/element |
. | @ | the current object/element |
/ | . or [] | child operator |
.. | n/a | parent operator |
// | .. | recursive descent. JSONPath borrows this syntax from E4X. |
* | * | wildcard. All objects/elements regardless their names. |
@ | n/a | attribute access. JSON structures don't have attributes. |
[] | [] | subscript operator. XPath uses it to iterate over element collections and for predicates. In Javascript and JSON it is the native array operator. |
| | [,] | Union operator in XPath results in a combination of node sets. JSONPath allows alternate names or array indices as a set. |
n/a | [start:end:step] | array slice operator borrowed from ES4. |
[] | ?() | applies a filter (script) expression. |
n/a | () | script expression, using the underlying script engine. |
() | n/a | grouping in Xpath |
JSONPath expressions can use the dot–notation
$.store.book[0].title
or the bracket–notation
$['store']['book'][0]['title']
The following XPath expression
/store/book[1]/title
JsonPath would look like
x.store.book[0].title
or
x['store']['book'][0]['title']
JSONPath examples
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{ "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 } } } |
XPath | JSONPath | Result |
/store/book/author |
$.store.book[*].author |
the authors of all books in the store |
//author |
$..author |
all authors |
/store/* |
$.store.* |
all things in store, which are some books and a red bicycle. |
/store//price |
$.store..price |
the price of everything in the store. |
//book[3] |
$..book[2] |
the third book |
//book[last()] |
$..book[(@.length-1)] $..book[-1:] |
the last book in order. |
//book[position()<3] |
$..book[0,1] $..book[:2] |
the first two books |
//book[isbn] |
$..book[?(@.isbn)] |
filter all books with isbn number |
//book[price<10] |
$..book[?(@.price<10)] |
filter all books cheapier than 10 |
//* |
$..* |
all Elements in XML document. All members of JSON structure. |
需要的JAR包
json-path-0.9.1.jar
json-smart-1.2.jar
commons-lang-2.6.jar