JSR-303 bean validation with Spring does not kick in

Question

I've configured a JSR-303 custom validator following what's given in the docs (http://docs.spring.io/spring/docs/4.0.x/spring-framework-reference/html/validation.html), complete with LocalValidatorFactoryBean and Hibernate validator on the classpath. However, my validator just refuses to kick in. I've put up a dirt simple test project here (https://github.com/abhijitsarkar/java/tree/master/spring-jsr-303), along with a failing unit test. Should you decide to take a look, just clone it and run gradlew clean test from the root directory. I'm using Spring framework 4.0.2.RELEASE and Hibernate validator 5.0.3.Final.

Method under validation:

public Coffee serve(@ValidOrder(Coffee.Blend.class) final String blend) {

ValidOrder annotation:

@Documented
@Constraint(validatedBy = {OrderValidator.class})
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD,
        ElementType.FIELD,
        ElementType.ANNOTATION_TYPE,
        ElementType.CONSTRUCTOR,
        ElementType.PARAMETER})
@NotNull
public @interface ValidOrder {

OrderValidator validator:

public class OrderValidator implements ConstraintValidator<ValidOrder, String> {

Spring config:

@Configuration
@ComponentScan(basePackages = "name.abhijitsarkar.coffeehouse")
@EnableAspectJAutoProxy
public abstract class AppConfig {

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

Dependencies:

dependencies {
    compile(
            [group: 'javax.inject', name: 'javax.inject', version: injectApiVersion],
            [group: 'javax.validation', name: 'validation-api', version: beanValidationApiVersion],
            [group: 'javax.annotation', name: 'javax.annotation-api', version: annotationApiVersion],
            [group: 'org.springframework', name: 'spring-beans', version: springVersion],
            [group: 'org.springframework', name: 'spring-context', version: springVersion],
            [group: 'org.springframework', name: 'spring-aop', version: springVersion],
            [group: 'org.aspectj', name: 'aspectjrt', version: aspectjVersion]
    )
    runtime(
            [group: 'org.hibernate', name: 'hibernate-validator', version: hibernateValidatorVersion],
            [group: 'javax.el', name: 'javax.el-api', version: elVersion],
            [group: 'org.glassfish.web', name: 'javax.el', version: glassfishElVersion],
            [group: 'org.aspectj', name: 'aspectjweaver', version: aspectjVersion]
    )

Answer 1

1. A MethodValidationPostProcessor needs to be configured in addition to the LocalValidatorFactoryBean.

2. The class to be validated must have a @Validated annotation on it else methods are NOT searched for inline constraint annotations.

   @Configuration
   @ComponentScan(basePackageClasses = {SpringPackageComponentScanMarker.class})
   @EnableAspectJAutoProxy
   public abstract class AppConfig {
   
   @Bean
   public MethodValidationPostProcessor methodValidationPostProcessor() {
       final MethodValidationPostProcessor methodValidationPostProcessor = new MethodValidationPostProcessor();
       methodValidationPostProcessor.setValidator(validator());
   
       return methodValidationPostProcessor;
   }
   
   @Bean
   public LocalValidatorFactoryBean validator() {
       final LocalValidatorFactoryBean localValidatorFactoryBean = new LocalValidatorFactoryBean();
   
       return localValidatorFactoryBean;
     }
   }
   

...

@Service
@Validated
public class SpringBarista extends Barista {

The part of the reference manual that talks about integration with JSR-303 conveniently omits these 2 crucial points without which BV does not kick in. This just caused me 6 hours of debugging and hair tearing where I did everything the doc said but BV would simply not kick in. I finally had to debug through the Spring source code to understand this. There got to be an easier way and I can't be the only one who had this problem. Created a JIRA SPR-11473 for them to update the doc.