How do you supply a ClockProvider to Spring v5 (Spring Boot v2)? - spring

Question

What is the proper way to supply your own ClockProvider to the ValidatorFactory configuration in Spring v5 (Spring Boot v2) so that it's used everywhere the Bean Validations Validator is injected?
Use Case: You want to provide a buffer on what it considers "Present", such as described in this blog post to account for a reasonable amount of clock drift.

Answer 1

The simplest solution, that also keeps all Spring defaults untouched, is to override method postProcessConfiguration():
#Configuration
class TimeConfiguration {
#Bean
static Clock clock() {
return Clock.fixed(
Instant.ofEpochSecond(1700000000), ZoneOffset.UTC
);
}
#Bean
static LocalValidatorFactoryBean defaultValidator(Clock clock) {
LocalValidatorFactoryBean factoryBean = new LocalValidatorFactoryBean() {
#Override
protected void postProcessConfiguration(
javax.validation.Configuration<?> configuration) {
configuration.clockProvider(() -> clock);
}
};
MessageInterpolatorFactory interpolatorFactory =
new MessageInterpolatorFactory();
factoryBean.setMessageInterpolator(interpolatorFactory.getObject());
return factoryBean;
}
}

Answer 2

Spring 5 is only runtime compatible with Bean Validation 2.0, which introduced ClockProvider you'd like to use. See next code from Spring sources. I think there are two ways you can go from this. You can try to use xml configuration for validator and specify clock provider there. It'll look something like this in your validation.xml:
<validation-config
xmlns="http://xmlns.jcp.org/xml/ns/validation/configuration"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/validation/configuration
http://xmlns.jcp.org/xml/ns/validation/configuration/validation-configuration-2.0.xsd"
version="2.0">
// any other configurations...
<clock-provider>com.acme.ClockProvider</clock-provider>
</validation-config>
Another option, if you don't like xml, would be to try define and use your own LocalValidatorFactoryBean.
Also note that maybe for your usecase it'll be useful to use a relatively new feature introduced in Hibernate Validator - temporal validation tolerance, which allow to specify a tolerance for temporal constraints. For more details about it see the documentation. This tolerance can also be set in xml as well as programatically.

Answer 3

Check this blogpost
#Bean
#ConditionalOnMissingBean(ClockProvider.class) // to allow tests to overwrite it
public ClockProvider getClockProvider() {
return () -> Clock.systemDefaultZone();
}