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javahibernate-validator

How to use Java Beans validation through hibernate-validation without a framework?

I'm using Java Beans validation through hibernate-validation on a JavaFX application, so, without a framework to help with the wiring. I added these dependencies to my project:

compile group: "org.hibernate", name: "hibernate-validator", version: "6.0.2.Final"
compile group: "org.glassfish", name: "javax.el", version: "3.0.1-b08"
compile group: "javax.validation", name: "validation-api", version: "2.0.0.Final"

and I found this works to get modelObject validated:

ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
Validator validator = factory.getValidator();
validator.validate(modelObject);

My question is, is it bad to create a new factory and validator every time I validate? Should I cache them somewhere and re-use them? How expensive and how multi-threaded are the validators?

Solution

  • Is it bad to create new ValidatorFactory each time?

    According to the javadoc note, the following is stated:

    • The ValidatorFactory object built by the bootstrap process should be cached and shared amongst Validator consumers.
    • This class is thread-safe.

    As of Validator, its implementations also expected to be thread-safe according to javadoc

    Working with javax.Validation in Spring

    You've tagged your question with 'Spring', therefore a brief notice on working with javax.validation + Spring correctly.

    First, use Spring LocalValidatorFactoryBean (as for example answered here), that will take care of necessary caching you're looking for:

    @Bean
public javax.validation.Validator localValidatorFactoryBean() {
   return new LocalValidatorFactoryBean();
}

    Second, inject Validator instances using Spring as well:

    @Autowired
private Validator validator;

    You can either let Spring do all the job. For example, to make validation-related annotations work for methods, define 

    @Bean
public MethodValidationPostProcessor methodValidationPostProcessor() {
    return new MethodValidationPostProcessor();
}

    in your Spring application configuration, and then you'll be able to call something like

    public void myMethod(@Valid MyValidationAnnotatedType parameter){
    ...
}

public void anotherMethod(@Pattern(regex = "^[A-Za-z]+$") stringParameter) {
    ...
}

    Please refer to Spring documentation for further details