Custom ConstraintValidator not invoked before persist - jpa

Question

#Target({TYPE, ANNOTATION_TYPE, FIELD})
#Retention(RUNTIME)
#Constraint(validatedBy = {UniqueNameValidator.class})
#Documented
public #interface UniqueName {
String message() default "Unique name constraint";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
public class UniqueNameValidator implements ConstraintValidator<UniqueName, Object> {
#Override
public void initialize(UniqueName constraintAnnotation) {
System.out.println("UniqueNameValidator -> initialize() method invoked!");
}
#Override
public boolean isValid(Object value, ConstraintValidatorContext context) {
System.out.println("UniqueNameValidator -> isValid method invoked!");
return true;
}
}
#Entity
public class MyClass implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Column(name = "ID")
private Long id;
#UniqueName
#Column(name = "NAME")
private String name;
//Getters & Setters
}
The dependencies used in my project are :
<dependency>
<groupId>com.sun.faces</groupId>
<artifactId>jsf-api</artifactId>
<version>2.2.18</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.sun.faces</groupId>
<artifactId>jsf-impl</artifactId>
<version>2.2.18</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>5.3.6.Final</version>
</dependency>
<dependency>
<groupId>javax.validation</groupId>
<artifactId>validation-api</artifactId>
<version>2.0.1.Final</version>
</dependency>
Env :
Java 8
WebLogic Server: 12.2.1.2.0
Eclipselink version 2.6.4
After trying many suggestions from SOF i can't figure out why my custom validator is not called before persisting the entity (Validation on class level or field level) !
Any help will be appreciated.