Java validator for UUIDs

UUID.java

import javax.validation.Constraint;
import javax.validation.Payload;
import javax.validation.constraints.Pattern;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import static java.lang.annotation.RetentionPolicy.RUNTIME;

/**
 * Validation constraint for a UUID in string format.
 *
 * e.g. 6cfb0496-fa35-4668-a970-78a873d7970e
 *
 * @author Rüdiger Schulz <rs@mindhaq.com>
 */
@Pattern(regexp = "^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$")

@Retention(RUNTIME)
@Target({METHOD, FIELD, PARAMETER, ANNOTATION_TYPE})
@Constraint(validatedBy = {})
@Documented
public @interface UUID {
    String message() default "UUID has wrong format";

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

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

You cannot apply the '@pattern' annotation to something (java.util.UUID) that is not a CharSequence

Right; this is meant for validating e.g. incoming path variables or request parameters in a spring MVC controller method.

@GetMapping("/change/{code}")
public String confirmChange(@PathVariable @UUID String code) { 
    // ...
}

I just created a bean validation annotation and requested a merge to Hibernate Validators. If you want to support this, just vote for it here:

• hibernate/hibernate-validator#1199
• https://hibernate.atlassian.net/browse/HV-1867