Spring MVC JSON Schema Validation

Validate Spring MVC Controller parameters against JSON schema. Just annotate them with @JsonRequestBody.

How does it work?

By adding @JsonRequestBody to the controller method parameter, we will be able to validate the corresponding parameter against JSON Schema.

@RequestMapping(method = RequestMethod.POST, value = "/boxes")
public void register(@JsonRequestBody BoxRequest request)

By convention, the request parameter will be validated against JSON schema available in the CLASSPATH, in the BoxController#register.json file.

Any schema validation error will be converted to the JsonSchemaValidationException which wraps standard Spring Errors instance. Such exception can be converted to the proper response by @ExceptionHandler mechanism and like.

Configuring

To enable this facility, register the JsonRequestBodyArgumentResolverRegisteringBeanPostProcessor bean in the application context.

@Bean
static BeanPostProcessor jsonRequestBodyArgumentResolverRegisteringBeanPostProcessor() {
    return new JsonRequestBodyArgumentResolverRegisteringBeanPostProcessor();
}

Note that the post processor bean method must be static, as per Spring Framework requirements for bean postprocessors.

For details and complex example, see unit tests and TestApplicationContext.

Requirements

• Spring Framework 4.2.0 or newer
• Everit JSON Schema validator

Advanced Usage

Combining JSON Schema validation and Spring MVC Validators

JSON Schema validation can be combined with the standard Spring MVC validation. Just pass the Errors instance as the following parameter and suppress the immediate validation exception throwing:

@RequestMapping(method = RequestMethod.POST, value = "/boxes")
public void register(@JsonRequestBody(strict = false) BoxRequest request, Errors errors)

By setting strict parameter to false, no validation exception will be thrown. Instead, all validation exceptions will be converted to the Errors validation errors.