Read me first

This project, as of version 2.1.8, is licensed under both LGPLv3 and ASL 2.0. See file LICENSE for more details. Versions 2.1.7 and lower are licensed under LGPLv3 only.

This implementation has complete validation support for the latest draft (v4) and the previous draft (v3). More generally, it has quite an extensive list of features.

Should you wonder about it, this library is reported to work on Android :)

Google Group

This project has a dedicated Google group. For any questions you have about this software package, feel free to post! The author (me) will try and respond in a timely manner.

Testing online

You can test this library online; this web site is in a project of its own, which you can fork and run by yourself.

Command line

Since 2.1.10, there is a command line application. For this, download the standalone jar from Bintray and run it. There are different options. Here is the output of --help:

$ java -Done-jar.silent=true -jar json-schema-validator-2.1.10-standalone.jar --help
Syntax: java -jar jsonschema.jar [options] file [file...]

Options: 
    -s, --brief: only show validation status (OK/NOT OK)
    --help: show this help
    -q, --quiet: no output; exit with the relevant return code (see below)
    --syntax: check the syntax of schema(s) given as argument(s)

Exit codes:
    0: validation successful;
    1: exception occurred (appears on stderr)
    2: command line syntax error (missing argument, etc)
    100: one or more file(s) failed validation
    101: one or more schema(s) is/are invalid

(note that -Done-jar.silent=true is needed for silent output; this is due to a bug in OneJar which is not silent by default; see here for more details)

Versioning scheme policy

The versioning scheme is defined by the middle digit of the version number:

• if this number is even, then this is the stable version; no new features will be added to such versions, and the user API will not change (save for some additions if requested).
• if this number is odd, then this is the development version; new features will be added to those versions only, and the user API may change.

Versions

• development version: 2.1.10 (ChangeLog, Javadoc, code samples).
• stable version: 2.0.3 (ChangeLog, Javadoc, code samples).

Since version 2.1.5, this package is available on Bintray.

Gradle/Maven artifact

Gradle:

dependencies {
    compile(group: "com.github.fge", name: "json-schema-validator", version: "yourVersionHere");
}

Maven:

<dependency>
    <groupId>com.github.fge</groupId>
    <artifactId>json-schema-validator</artifactId>
    <version>your-version-here</version>
</dependency>

Extending usage beyond validation

This library's dependency on json-schema-core opens up many possibilities for extensions. A dedicated project already has a few examples.

The site mentioned above already has a few examples of what is possible. Much more is doable. In fact, the only limiting factor is your own imagination!

Relevant documents

This implementation is based on the following drafts:

• JSON Schema Internet draft, version 4 (link to validation spec);
• JSON Schema Internet draft, version 3;
• JSON Reference Internet draft, version 3;
• JSON Pointer (RFC 6901).

More...

For a detailed discussion of the implementation, see here.

Please see the wiki for more details.