using validators in spring-data-rest returns http 500 instead of 400

Question

I'm trying to get the validation in spring-data-rest to work. From the documentation you only need to make a validator available, and I've got that to work, but when a validation constraint is successfully caught/processed I get a 500 error page with the stack trace.

In the config class, RepositoryRestMvcConfiguration it has a validationExceptionHandler which looks like it should get such validation errors to return as 400 rather than 500. It is also a lazy loaded bean.

Do I have an incorrect setup? or is there another way to get spring-data-rest to return 400 instead of 500?

I'm using spring-data-rest version 2.0.0 Release

Stack trace return by tomcat:

HTTP Status 500 - Request processing failed; nested exception is javax.validation.ConstraintViolationException: Validation failed for classes [test.domain.Account] during persist time for groups [javax.validation.groups.Default, ]

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is javax.validation.ConstraintViolationException: Validation failed for classes [test.domain.Account] during persist time for groups [javax.validation.groups.Default, ]
List of constraint violations:[
    ConstraintViolationImpl{interpolatedMessage='size must be between 0 and 10', propertyPath=login, rootBeanClass=class test.domain.Account, messageTemplate='{javax.validation.constraints.Size.message}'}
]
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:965)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:855)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:647)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:829)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

Account Entity:

@Entity
public class Account {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    Long id;

    @Column(unique = true)
    @Size(max = 10)
    String login;

}

RestMvcConfig:

@Configuration
public class RestExporterRestConfig extends RepositoryRestMvcConfiguration {}

Answer 1

Seem to have got it working; i had to override the validatingRepositoryEventListener() and manually add validators to the listener;

@Configuration
public class RestExporterRestConfig extends RepositoryRestMvcConfiguration {

    @Bean
    public Validator validator() {
        return new LocalValidatorFactoryBean();
    }

    @Bean
    @Override
    public ValidatingRepositoryEventListener validatingRepositoryEventListener() {
        ValidatingRepositoryEventListener listener = new ValidatingRepositoryEventListener();
        configureValidatingRepositoryEventListener(listener);
        listener.addValidator("afterCreate", validator());
        listener.addValidator("beforeCreate", validator());
        return listener;
    }

}

I now get a 400 returned as follows;

400 Bad Request
{"errors":
    [{  "entity":"Account",
        "message":"size must be between 0 and 10",
        "invalidValue":"login 0dsfdsfdsfdsfdsfdsfdsfds",
        "property":"login"
    }]
}