Creating a custom validation for bean validation in spring boot
Why we create a custom bean validation?
To test whether the input are valid one before the inputs reach our application.
How to create a custom annotation java code?
/**
* Custom annotation
*/
package com.javabelazy.validators;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Repeatable;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import javax.validation.Constraint;
import javax.validation.Payload;
/**
* @author Java code
*
*/
@Target({ ElementType.METHOD, ElementType.FIELD })
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Constraint(validatedBy = { OrderStatusValidator.class })
public @interface Status {
String message() default "Invalid order status";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
}
@Target denotes the context where the annotation type is applicable, here we mentioned on a method or a field.
@Retention denotes the annotation is available at the run time.
@Constraint denotes the class where the validation logic is implemented
How to create a custom validator?
/**
* Custom annotation validator class
*/
package com.javabelazy.validators;
import java.util.stream.Stream;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
/**
* @author Java source code
*
*/
public class OrderStatusValidator implements ConstraintValidator<Status, String> {
@Override
public void initialize(Status constraintAnnotation) {
}
@Override
public boolean isValid(String orderStatus, ConstraintValidatorContext context) {
System.out.println(" ****** "+orderStatus);
if (orderStatus.isBlank()) {
return true;
}
boolean isValid = Stream.of(OrderStatus.values()).anyMatch(v -> v.name().equals(orderStatus));
return isValid;
}
}
How to use this annotation?
@Status
private String orderStatus;
Thanks
