Assign value to wrapper throw null exception

Question

I have a JSON String Need to pass as request body with configurabale parameter as below.I have used a wrapper class for that called as EmailWrapper , but here assign value to wrapper.options.fieldOne ,throw Attempt to de-reference a null object but threatMapping.Field1__c has value. I think I have access wrapper in incorrect way. Can someone help me on this?

public with sharing class TestValid {

    @AuraEnabled(cacheable=true)
    public static void emailValidation(String email){
        EmailOptionAttributes emailOptions = new EmailOptionAttributes();
        EmailWrapper wrapper = new EmailWrapper();
        System.debug('email====-: ' +email);
        if(email != null){
            System.debug('email====-: ' +email);
            wrapper.emailValue = email;
            System.debug('email2====-: ' +email);
        }
        Email_validation__mdt[] emailValidation = [SELECT Field1__c,Field2__c,Field3__c,Field4__c,Field5__c FROM Email_validation__mdt];
        System.debug('emailValidation' +emailValidation);
        for (Email_validation__mdt threatMapping : emailValidation) {
            wrapper.options.fieldOne = threatMapping.Field1__c;
            wrapper.options.fieldTwo = threatMapping.Field2__c;
            wrapper.options.fieldThree =  threatMapping.Field3__c;
            wrapper.options.fieldFour = threatMapping.Field4__c;
            wrapper.options.fieldFive = threatMapping.Field5__c;
        }
        System.debug('emailOptions: ' +emailOptions);
        String jsonString = JSON.serialize(emailOptions);
        System.debug('jsonString: ' +jsonString);

    }

    public class EmailOptionAttributes {
        public  Boolean fieldOne;
        public  Boolean fieldTwo;
        public  Boolean fieldThree;
        public  Boolean fieldFour;
        public  Boolean fieldFive;
    }

    public class EmailWrapper{
        public String emailValue;
        public EmailOptionAttributes options;
    }
}

Answer 1

You defined emailOptions at the beginning of your method (a new EmailOptionAttributes) but are not doing anything with it, as instead you're trying to access wrapper.options that is null at this point.

Instead, you can populate the properties of emailOptions and then assign this value to wrapper's options field.

Taking your emailValidation method into consideration, it would be somehow similar to:

@AuraEnabled(cacheable=true)
    public static void emailValidation(String email){
        EmailOptionAttributes emailOptions = new EmailOptionAttributes();
        EmailWrapper wrapper = new EmailWrapper();
        System.debug('email====-: ' +email);
        if(email != null){
            System.debug('email====-: ' +email);
            wrapper.emailValue = email;
            System.debug('email2====-: ' +email);
        }
        Email_validation__mdt[] emailValidation = [SELECT Field1__c,Field2__c,Field3__c,Field4__c,Field5__c FROM Email_validation__mdt];
        System.debug('emailValidation' +emailValidation);
        for (Email_validation__mdt threatMapping : emailValidation) {
            emailOptions.fieldOne = threatMapping.Field1__c;
            emailOptions.fieldTwo = threatMapping.Field2__c;
            emailOptions.fieldThree =  threatMapping.Field3__c;
            emailOptions.fieldFour = threatMapping.Field4__c;
            emailOptions.fieldFive = threatMapping.Field5__c;
        }
        wrapper.options = emailOptions;

        System.debug('emailOptions: ' +emailOptions);
        String jsonString = JSON.serialize(emailOptions);
        System.debug('jsonString: ' +jsonString);

    }

Best regards!