December 02, 2013

how to obtain a validator

To obtain a Validator, you must first create a ValidatorFactory. If there is only one Bean Validation implementation in your classpath, you can use:

ValidatorFactory vf = Validation.buildDefaultValidatorFactory();

You should usually not instantiate more than one factory; factory creation is a costly process. Also, the factory also acts as a cache for the available validation constraints. Below is an example that will create a singleton ValidatorFactory and will let you obtain Validators from it:

public enum MyValidatorFactory {
        ValidatorFactory avf =
        public Validator getValidator() {
            return avf.getValidator();
    public abstract Validator getValidator(); 
} Using the above class, obtaining a Validator just requires you to call:


Using The Spring Framework

If you are using Spring, you can easily inject Validators into your beans. Simply configure the factory in your ApplicationContext by adding:

<!-- Validator bean -->
<bean id="validator"
    <property name="providerClass"
        value="org.apache.bval.jsr303.ApacheValidationProvider" />
</bean> And Spring will be able to inject Validators and the ValidatorFactory into your beans.


这里使用的是apache bval, 一般使用hibernate的实现.


2016年05月Reading Notes

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2016年05月Reading Notes

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