Validator component

The validator component checks the XML message body against an XML Schema (XSD) and fails the exchange with a SchemaValidationException listing every error when it does not conform.

Scheme: validator: · Crate: cameleer-xml · Cargo feature: none for a well-formedness check; xml for full XML Schema validation · Consumer: no · Producer: yes · Apache Camel: Validator

When to use it

• Reject malformed partner documents (orders, invoices, HL7 v3, UBL) at the edge of a route.
• Check XML produced by an LLM or a transformation before sending it to a strict backend.
• Route invalid documents to a dead letter or error queue with doTry / onException.

URI format

validator:schemaResource[?options]

schemaResource is a file path relative to the working directory, file:path, classpath:path (read as a relative path) or ref:beanName. xs:include and xs:import resolve relative to the schema file.

Example

Validate orders and answer with the validation errors instead of failing the caller.

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="order">
    <xs:complexType>
      <xs:sequence>
        <xs:element name="customer" type="xs:string"/>
        <xs:element name="qty" type="xs:positiveInteger"/>
      </xs:sequence>
      <xs:attribute name="id" type="xs:string" use="required"/>
    </xs:complexType>
  </xs:element>
</xs:schema>

- route:
    id: validator-order
    from:
      uri: direct:validator-order
      steps:
        - doTry:
            steps:
              - to: validator:xsd/order.xsd
              - setBody:
                  constant: valid
            doCatch:
              - exception:
                  - org.apache.camel.ValidationException
                steps:
                  - setBody:
                      simple: "invalid: ${exception.message}"

A valid order:

<order id="o-1"><customer>Ada</customer><qty>2</qty></order>

valid

An order with a missing attribute and a negative quantity:

<order><customer>Ada</customer><qty>-1</qty></order>

invalid: Validation failed for: xsd/order.xsd
cvc-complex-type.4
cvc-datatype-valid.1.2.1

SchemaValidationException is a ValidationException, so the catch above takes both schema errors and documents that are not well-formed.

Rust DSL

b.from("direct:validator-rust")
    .to("validator:xsd/order.xsd")
    .set_body(constant("valid"));

Options

Accepted and ignored (Java-only settings): schemaFactory, schemaLanguage, resourceResolver, resourceResolverFactory, errorHandler, useDom, schemaReaderFactory, lazyStartProducer.

Supported XML Schema

A subset of XML Schema 1.0: global and local elements, ref, minOccurs / maxOccurs, sequence / choice / all, model groups, attributes, simple types with restrictions (facets), the built-in data types, include and import. Without cameleer-xml registered, cameleer-core's validator only checks well-formedness; cameleer_main::new_main() and the cameleer CLI always register the full validator.

Message headers

Run it with Docker

docker run --rm -v "$PWD:/routes:ro" pmsudhi/cameleer run /routes/validate.camel.yaml

Common questions

How do I get all validation errors, not just the first?

The exception message lists every error, and the CamelValidationErrors exchange property holds them as a list.

How do I validate a header instead of the body?

Set headerName=myHeader.

Does it also catch XML that is not well-formed?

Yes. A parse error fails with SchemaValidationException too, as Xerces reports it through the same error handler in Camel.

Related

• json-validator for JSON Schema.
• xslt, xmlsecurity-verify.
• Apache Camel Validator component

Found a problem?

If something on this page doesn't match what Cameleer does, or you hit a bug while building with it, please help fix it, whether you are a person or a coding agent: open an issue that describes what you saw, then fork the repository, fix it, add or update a test, run cargo test --workspace, and open a pull request. CONTRIBUTING.md explains the ground rules.