Creating a custom validation for bean validation in spring boot

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