Master JSONPath in Spring Boot: Extract and Manipulate JSON Like a Pro

Introduction

When dealing with complex JSON structures, manually creating Java POJOs or Maps is cumbersome. JSONPath provides an XPath‑like expression language to query, filter, transform, and update JSON data efficiently.

Environment

Spring Boot 3.4.0 is used. Add the json‑path dependency (version managed by Spring Boot):

<code>&lt;dependency&gt;
  &lt;groupId&gt;com.jayway.jsonpath&lt;/groupId&gt;
  &lt;artifactId&gt;json-path&lt;/artifactId&gt;
&lt;/dependency&gt;
</code>

Syntax Overview

Key operators:

$ – Root element of the query.

@ – Current node processed by a filter predicate.

* – Wildcard for any name or index.

.. – Recursive descent.

.<name> – Dot notation for child nodes.

['<name>'] – Bracket notation for child nodes or collections.

[<number>] – Array index or list of indices.

[start:end] – Array slice.

[?(<expression>)] – Filter expression that must evaluate to a boolean.

Filter Operators

== – Equality (note: 1 ≠ '1').

!= – Inequality.

< – Less than.

<= – Less than or equal.

> – Greater than.

>= – Greater than or equal.

=~ – Regex match.

in – Left value exists in right collection.

nin – Left value does not exist in right collection.

subsetof – Left value is a subset of right collection.

anyof – Intersection exists.

noneof – No intersection.

size – Size of array or string matches right value.

empty – Array or string is empty.

Practical Example

Sample JSON data:

<code>{
  "store": {
    "book": [
      { "category": "Java", "author": "张三", "title": "Java从入门到放弃", "price": 88.6 },
      { "category": "Spring", "author": "Pack", "title": "Spring从入门到精通", "price": 99.8 },
      { "category": "Java", "author": "李四", "title": "多线程并发编程", "isbn": "1-9527-6688-9", "price": 66.9 },
      { "category": "Spring", "author": "Pack", "title": "Spring Boot3实战案例100讲", "isbn": "6-9527-7799-2", "price": 70 }
    ],
    "bicycle": { "color": "red", "price": 666 }
  },
  "expensive": 10
}
</code>

Reading the JSON file in Spring Boot:

<code>String json = new ClassPathResource("data.json")
    .getContentAsString(StandardCharsets.UTF_8);
</code>

Examples of JSONPath queries:

All authors: $.store.book[*].author

All authors using recursive descent: $..author

All data under store : $.store.*

All prices: $.store..price

Third book (index 2): $..book[2]

Books with an ISBN: $..book[?(@.isbn)]

Books cheaper than 70: $.store.book[?(@.price < 70)]

Number of books: $..book.length()

Custom filter example (Java code):

<code>Filter cheapFictionFilter = filter(
    where("category").is("Java")
    .and("price").lte(70D)
);
List<Map<String, Object>> books = JsonPath.parse(json)
    .read("$.store.book[?]", cheapFictionFilter);
</code>

Modifying JSON data:

<code>String newJson = JsonPath.parse(json)
    .set("$['store']['book'][0]['author']", "pack_xg")
    .jsonString();
</code>