components/camel-json-validator/src/main/docs/json-validator-component.adoc

= JSON Schema Validator Component
:doctitle: JSON Schema Validator
:shortname: json-validator
:artifactid: camel-json-validator
:description: Validate JSON payloads using NetworkNT JSON Schema.
:since: 2.20
:supportlevel: Stable
:tabs-sync-option:
:component-header: Only producer is supported

*Since Camel {since}*

*{component-header}*

The JSON Schema Validator component performs bean validation of the message body
against JSON Schemas v4, v6, v7, v2019-09 draft and v2020-12(partial) using the NetworkNT JSON Schema library
(https://github.com/networknt/json-schema-validator).

Maven users will need to add the following dependency to their `pom.xml`
for this component:

[source,xml]
----
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-json-validator</artifactId>
    <version>x.y.z</version>
    <!-- use the same version as your Camel core version -->
</dependency>
----


== URI format

----
json-validator:resourceUri[?options]
----

Where *resourceUri* is some URL to a local resource on the classpath or a
full URL to a remote resource or resource on the file system which contains 
the JSON Schema to validate against.
 

// component options: START
include::partial$component-configure-options.adoc[]
include::partial$component-endpoint-options.adoc[]
include::partial$component-endpoint-headers.adoc[]
// component options: END


== Example

Assuming we have the following JSON Schema:

*myschema.json*

[source,json]
----
{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "definitions": {}, 
  "id": "my-schema",
  "properties": {
    "id": {
      "default": 1, 
      "description": "An explanation about the purpose of this instance.", 
      "id": "/properties/id", 
      "title": "The id schema", 
      "type": "integer"
    }, 
    "name": {
      "default": "A green door", 
      "description": "An explanation about the purpose of this instance.", 
      "id": "/properties/name", 
      "title": "The name schema", 
      "type": "string"
    }, 
    "price": {
      "default": 12.5, 
      "description": "An explanation about the purpose of this instance.", 
      "id": "/properties/price", 
      "title": "The price schema", 
      "type": "number"
    }
  }, 
  "required": [
    "name", 
    "id", 
    "price"
  ], 
  "type": "object"
}
----

We can validate incoming JSON with the following Camel route, where `myschema.json` is loaded from the classpath.

[tabs]
====
Java::
+
[source,java]
----
from("direct:start")
    .to("json-validator:myschema.json")
    .to("mock:end");
----

XML::
+
[source,xml]
----
<route>
  <from uri="direct:start"/>
  <to uri="json-validator:myschema.json"/>
  <to uri="mock:end"/>
</route>
----

YAML::
+
[source,yaml]
----
- route:
    from:
      uri: direct:start
      steps:
        - to:
            uri: json-validator:myschema.json
        - to:
            uri: mock:end
----
====

If you use the default schema loader, it will try to determine the schema version from the $schema property and instruct the https://github.com/networknt[validator] appropriately.  If it can't find (or doesn't recognize) the $schema property, it will assume your schema is version https://json-schema.org/specification-links.html#draft-2019-09-formerly-known-as-draft-8[2019-09].

If your schema is local to your application (e.g. a classpath location as opposed to URL), your schema can also contain `$ref` links to a relative subschema in the classpath.  Per the JSON schema spec, your schema must not have an $id identifier property for this to work properly.  See the https://github.com/apache/camel/blob/main/components/camel-json-validator/src/test/java/org/apache/camel/component/jsonvalidator/LocalRefSchemaTest.java[unit test] and https://github.com/apache/camel/blob/main/components/camel-json-validator/src/test/resources/org/apache/camel/component/jsonvalidator/Order.json[schema] for an example.