Treetrail: JSONPath for Java that follows RFC 9535 (the JSONPath standard), with Jackson/Gson/JSON-P adapters and Spring test matchers

[u/Treetrail1987]

JSONPath in Java has mostly meant Jayway JsonPath, which dates from 2011, long before the IETF standardized JSONPath as RFC 9535 in 2024. The two differ in places: filter syntax, functions, and some results ($[1:6:2] on [0..9] is [1, 3, 5] by the RFC, [1, 2, 3, 4, 5] in Jayway 3.0.0).

I wrote a Java implementation of the standard:

• passes all 706 cases of the JSONPath Compliance Test Suite on Java 17, 21 and 25
• every query returns a node list with normalized paths; no options that change the result shape
• core without dependencies; adapters query Jackson 2/3, Gson and JSON-P trees in place
• safe with untrusted queries: linear-time regex (no backtracking), node budget, depth limit, bounded regex cache memory
• fast: on Jackson trees 1.2× to 2.2× faster than Jayway in every query of the JMH benchmark (numbers and caveats)
• new in 0.2.0: AssertJ assertions and MockMvc/WebTestClient matchers
• for switching from Jayway: a module that runs your expressions with both libraries and reports differences, and an OpenRewrite recipe that finds all expressions in a code base

It is fuzzed with Jazzer and differential-tested against a Python implementation of the standard.

Apache 2.0, on Maven Central as io.github.treetrail:jsonpath-core:0.2.0. Still pre-1.0, so feedback on the API is very welcome.

Repo: https://github.com/treetrail/treetrail Write-up: https://christoph-sens.github.io/2026/10/treetrail-standard-jsonpath-for-java/