JAVA > Hibernate > Custom Validator Simple Sample

gistfile1.java

package com.xpto.domain.model.validator;

import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.*;

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = PhotoExtensionValidator.class)
@Documented
public @interface PhotoExtension {

    String message() default "Extension not valid";

    Class<?>[] groups() default {};

    Class<? extends Payload>[] payload() default {};

    PhotoExtensionType extension();
}

public enum PhotoExtensionType {

    JPG,
    GIF
}

package com.xpto.domain.model.validator;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

public class PhotoExtensionValidator implements ConstraintValidator<PhotoExtension, String> {

    private PhotoExtensionType extension;
    private String message;

    @Override
    public void initialize(final PhotoExtension constraintAnnotation) {

        this.extension = constraintAnnotation.extension();
        this.message = constraintAnnotation.message();
    }

    @Override
    public boolean isValid(final String value, final ConstraintValidatorContext context) {

        return value == null ? true :
                value.toUpperCase().endsWith(this.extension.toString().toUpperCase());
    }
}