Package org.apache.daffodil.api.validation

package org.apache.daffodil.api.validation
Daffodil Validation API package

Daffodil provides a number of built-in validators for use with DataProcessor.withValidation(String, URL). For each built-in validator, the following contains the validator name, a description, and validator specific properties. The String parameter should be the name of the validator. If the URI parameter ends in .conf or .properties then it is treated as a Properties file that provides validator properties. Otherwise, the URI is set to a property with the same name as the validator. If a validator does not require properties, the URI parameter can be set to null or excluded.

off

Description: disable validation

Properties: none

Example:


 // explicitly disable validation
 dataProcessor.withValidation("off")
daffodil

Description: XML schema validation using Daffodil

Properties: none

Example:


 // enable XML schema validation using Daffodil
 dataProcessor.withValidation("daffodil")
xerces

Description: XML Schema validation using Xerces library

Properties:

xerces
absolute URI to a XSD file

Example:


 // enable XML schema validation, setting the "xerces" property to the schema.xsd file
 dataProcessor.withValidation("xerces", new URL("file:///path/to/schema.xsd"))
schematron

Description: schematron validation using Saxon-HE library

Properties:

schematron
absolute URI to a file containing schematron rules. If the URI ends with .sch then the file is treated as a schematron file. Otherwise, it is treated as an XSD file containing embedded schematron rules.
schematron.svrl.file
absolute URI to a file to write the results of schematron validation in SVRL format. This property is not thread safe and will overwrite existing files--it is intended primarily for debugging with single file validation.

Example:


 // enable schematron validation, setting the "schematron" property to the schematron.sch file
 dataProcessor.withValidation("schematron", new URL("file:///path/to/schematron.sch"))

 // use schematron validation, reading the schematron.properties file to set "schematron" or other schematron properties
 dataProcessor.withValidation("schematron", new URL("file:///path/to/schematron.properties"))

Custom Validators

Daffodil also supports custom validators. To make a custom validator available to Daffodil, follow these steps:

  1. Create a custom class that implements the Validator interface
  2. Create a custom class that implements the ValidatorFactory interface, whose make method returns the custom Validator from the previous step
  3. Register the custom ValidatorFactory by creating a ValidatorFactory file in META-INF/services/, its contents being the fully qualified name of the custom validator factory
  4. Call the DataProcessor.withValidation(String, URL) function, providing the name of the validator and optional URI.
  • Class
    Description
    ValidationHandler
    Validation Handler class to facilitate handling validation errors
    Validator
    Implement this trait to provide custom validation logic
    ValidatorFactory
    Implement this trait and register with SPI to provide runtime discovery of Validator implementations
    ValidatorInitializationException
    Exception to be thrown when initialization of a validator fails
    ValidatorNotRegisteredException
    Exception thrown for failed registration of a validator
    Validators
    Access SPI registered ValidatorFactory instances.