The Problem
Recently using MongoDB and Spring Data I encountered an interesting issue. Saving an Entity which was loaded by @DBRef(lazy = true) wasn’t possible together with the activated ValidatingMongoEventListener. Each time the following error occurred:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 |
javax.validation.ConstraintViolationException at org.springframework.data.mongodb.core.mapping.event.ValidatingMongoEventListener.onBeforeSave(ValidatingMongoEventListener.java:65) at org.springframework.data.mongodb.core.mapping.event.AbstractMongoEventListener.onBeforeSave(AbstractMongoEventListener.java:144) at org.springframework.data.mongodb.core.mapping.event.AbstractMongoEventListener.onApplicationEvent(AbstractMongoEventListener.java:90) at org.springframework.data.mongodb.core.mapping.event.AbstractMongoEventListener.onApplicationEvent(AbstractMongoEventListener.java:33) at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:163) at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:136) at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:381) at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:335) at org.springframework.data.mongodb.core.MongoTemplate.maybeEmitEvent(MongoTemplate.java:1633) at org.springframework.data.mongodb.core.MongoTemplate.doSave(MongoTemplate.java:986) at org.springframework.data.mongodb.core.MongoTemplate.save(MongoTemplate.java:933) at org.springframework.data.mongodb.repository.support.SimpleMongoRepository.save(SimpleMongoRepository.java:78) |
The Issue
Well looking into the details it is quite clear — as an dynamic proxy is passed to the validation which fields are all null. As so any validation on the Entity will always fail. The code of the validator itself down’t really show the obvious miss take — only if you compare it with the save method the problem gets pretty clear:
ValidatingMongoEventListener
|
1 2 3 4 5 6 7 8 9 10 11 |
public void onBeforeSave(Object source, DBObject dbo) { LOG.debug("Validating object: {}", source); Set violations = validator.validate(source); if (!violations.isEmpty()) { LOG.info("During object: {} validation violations found: {}", source, violations); throw new ConstraintViolationException(violations); } } |
MappingMongoConverter
Compared to the Spring Mongo Mapper code, which is responsible to store the entity it’s clear what we have to do.
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 |
public void write(final Object obj, final DBObject dbo) { if (null == obj) { return; } Class<?> entityType = obj.getClass(); boolean handledByCustomConverter = conversions.getCustomWriteTarget(entityType, DBObject.class) != null; TypeInformation<? extends Object> type = ClassTypeInformation.from(entityType); if (!handledByCustomConverter && !(dbo instanceof BasicDBList)) { typeMapper.writeType(type, dbo); } Object target = obj instanceof LazyLoadingProxy ? ((LazyLoadingProxy) obj).getTarget() : obj; writeInternal(target, dbo, type); } |
Solution
As so we have to replace the Spring provided Validation Listener with an own — till Spring fixes the issue:
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 |
public class FixedMongoValidation extends AbstractMongoEventListener<Object> { private final Validator validator; public FixedMongoValidation(Validator validator) { Assert.notNull(validator); this.validator = validator; } @Override @SuppressWarnings({ "rawtypes", "unchecked" }) public void onBeforeSave(Object obj, DBObject dbo) { Object target = obj instanceof LazyLoadingProxy ? ((LazyLoadingProxy) obj).getTarget() : obj; Set violations = validator.validate(target); if (!violations.isEmpty()) { LOG.info("During object: {} validation violations found: {}", target, violations); throw new ConstraintViolationException(violations); } } } |
And of course don’t forget to change the configuration to ensure your fixed class is used.
|
1 2 3 4 5 6 7 8 9 |
// JSR Validation for MongoDB Entities @Bean public ValidatingMongoEventListener validatingMongoEventListener() { return new ValidatingMongoEventListener(validator()); } @Bean public LocalValidatorFactoryBean validator() { return new LocalValidatorFactoryBean(); } |
Hi there!
I am having the same issue and followed your same steps. However, both my custom validation listener and Spring’s are being executed.
I am using Spring 3.2.9 and XML configuration instead, and tried the following configurations:
Any help fixing this issue would be more than appreciated 😉
Seems that posts in this website do not allow XML code… :-(. In any case, should not FixedMongoValidation be somehow specified in the configuration class? Thanks!
Yes it needs to be defined in the configuration class / xml. The described behavior points that both validator classes are in the Spring Context active in your case now. (The fixed one and the broken from Spring).
I would check where the current spring validator is coming from. Either from a imported namespace or some auto magic. Usually (in spring-data) the validator isn’t configured by default. I would assume the same for here now for the XML configuration. –> Means I think you have somewhere in XML the spring validator too. Does this make sense?
The question is also not about the spring core version but Spring Data / Mongo version. Nevertheless my patch till now didn’t made it into the lib, I can say for sure that
spring-data-mongodbis affected until version1.9.1.RELEASE.