I am writing a test class, and its failing because of Jason parser nullPointer Error. can someone tell me what is wrong with my code? I need help as soon as possible. 

here is main class : 

=================
public class IDMSIFWUserMapping {
    public static String usermapping(User userRec){
        Userrecord userRecord=new Userrecord();
        //Added as part of IC-2651
        List<User> usr = new List<User>();
        if(String.isNotBlank(userRec.FederationIdentifier)){
            usr = [SELECT Contact.Account.PRMIncludeCompanyInfoInSearchResults__c FROM User WHERE
                    FederationIdentifier=:userRec.FederationIdentifier];
        }

        if(userRec.Id != null) {
            userRecord.Id = userRec.Id;
        }
        userRecord.Email=userRec.Email;
        userRecord.mobilePhone=userRec.MobilePhone;
        userRecord.firstName=userRec.FirstName;
        userRecord.lastName=userRec.LastName;
        userRecord.countryCode=userRec.Country;
        userRecord.languageCode=userRec.IDMS_PreferredLanguage__c;
        //userRecord.Email=userRec.DefaultCurrencyIsoCode;
        userRecord.street=userRec.Street;
        userRecord.city=userRec.City;
        userRecord.zipCode=userRec.PostalCode;
        userRecord.stateOrProvinceCode=userRec.State;//'BJ';
        userRecord.county=userRec.IDMS_County__c;
        userRecord.pOBox=userRec.IDMS_POBox__c;
        userRecord.additionalAddress=userRec.IDMS_AdditionalAddress__c;
        userRecord.middleName=userRec.IDMSMiddleName__c;
        userRecord.salutation=userRec.IDMSSalutation__c;
        userRecord.fax=userRec.Fax;
        userRecord.accountId=userRec.BFO_ACCOUNT_ID__c;
        userRecord.userContext=userRec.IDMS_User_Context__c;
        userRecord.registrationSource=userRec.IDMS_Registration_Source__c;
        userRecord.emailOptIn=userRec.IDMS_Email_opt_in__c;
        if(userRec.IDMSHashedToken__c!=null && userRec.IDMSHashedToken__c!='') userRecord.hashedPin=userRec.IDMSHashedToken__c;
        if(userRec.IDMS_Federated_Id__c!=null && userRec.IDMS_Federated_Id__c!='') userRecord.idmsFederatedId=userRec.IDMS_Federated_Id__c;
        if(userRec.IDMSCompanyFederationIdentifier__c!=null && userRec.IDMSCompanyFederationIdentifier__c!='') userRecord.companyFederatedId=userRec.IDMSCompanyFederationIdentifier__c;
        
        //IC-2525 channel, sub-channel,isPrimaryContact
        userRecord.channel = userRec.Channel__c;
        userRecord.subChannel = userRec.SubChannel__c;
        userRecord.IDMSPrimaryContact = userRec.IDMSPrimaryContact__c;
        userRecord.contactId = userRec.ContactId;
        //Company Details
        userRecord.companyName=userRec.CompanyName;
        userRecord.companyStreet=userRec.Company_Address1__c;
        userRecord.companyCity=userRec.Company_City__c;
        userRecord.companyZipCode=userRec.Company_Postal_Code__c;
        userRecord.companyCountryCode=userRec.Company_Country__c;
        userRecord.companyStateOrProvinceCode=userRec.Company_State__c;//'BJ';
        userRecord.companyPOBox=userRec.IDMSCompanyPoBox__c;
        userRecord.companyCounty=userRec.IDMSCompanyCounty__c;
        userRecord.companyAdditionalAddress=userRec.Company_Address2__c;
        userRecord.classLevel1=userRec.IDMSClassLevel1__c;
        userRecord.classLevel2=userRec.IDMSClassLevel2__c;
        userRecord.marketSegment=userRec.IDMSMarketSegment__c;
        userRecord.marketSubSegment=userRec.IDMSMarketSubSegment__c;
        userRecord.marketServed=userRec.IDMSCompanyMarketServed__c;
        userRecord.employeeSize=userRec.IDMSCompanyNbrEmployees__c;
        userRecord.headquarter=String.Valueof(userRec.IDMSCompanyHeadquarters__c);
        userRecord.annualRevenue=String.Valueof(userRec.IDMSAnnualRevenue__c);
        userRecord.taxIdentificationNumber=userRec.IDMSTaxIdentificationNumber__c;
        userRecord.companyWebsite=userRec.Company_Website__c;
        userRecord.jobTitle=userRec.Job_Title__c;
        userRecord.jobFunction=userRec.Job_Function__c;
        userRecord.workPhone=userRec.Phone;
        userRecord.jobDescription=userRec.IDMSJobDescription__c;
        userRecord.profileLastUpdateSource = userRec.IDMS_Profile_update_source__c;
        //Added as part of IC-2651
        userRecord.companyPhone = userRec.IDMSWorkPhone__c;
        System.debug(userRec.RegistrationAttributes__c);
        userRecord.registrationAttributes=(List<IDMSIFWUserMapping.RegistrationAttributes>) JSON.deserialize(userRec.RegistrationAttributes__c,List<IDMSIFWUserMapping.RegistrationAttributes>.class);
        System.debug(userRecord.registrationAttributes);
        //currency
        //department
        //password
        //userRecord.companyDetails=companyDetails;
        string jsonRequest=JSON.serialize(userRecord,true);
        return jsonRequest;
    }
    
    
    
    public class Userrecord{
        public String Id;
        public string userContext ;
        public string salutation ;
        public string firstName ;
        public string middleName ;
        public string lastName ;
        public string countryCode ;
        public string email ;
        public string mobilePhone ;
        public string languageCode ;
        public string emailOptIn ;
        public string street ;
        public string city ;
        public string zipCode ;
        public string stateOrProvinceCode ;
        public string county ;
        public string pOBox ;
        public string additionalAddress ;
        public string suffix ;
        public string fax ;
        public string accountId ;
        public string registrationSource ;
        public string channel;
        public string subChannel;
        public string contactId;
        public boolean IDMSPrimaryContact;
        //public CompanyDetails companyDetails ;
        public string trustedAdmin;
        public string idmsFederatedId;
        public string hashedPin;
        //public string aboutMe;
        
        public string companyName ;
        public string companyStreet ;
        public string companyCity ;
        public string companyZipCode ;
        public string companyStateOrProvinceCode ;
        public string companyPOBox ;
        public string companyCounty ;
        public string companyCountryCode ;
        public string companyAdditionalAddress ;
        public string companyWebsite ;
        public string classLevel1 ;
        public string classLevel2 ;
        public string marketSegment ;
        public string marketSubSegment ;
        public string marketServed ;
        public string employeeSize ;
        public string department ;
        public string headquarter ;
        public string annualRevenue ;
        public string taxIdentificationNumber ;
        public string jobTitle ;
        public string jobFunction ;
        public string jobDescription ;
        public string workPhone ;
        public string companyFederatedId;
        public string profileLastUpdateSource;
        public String companyPhone;
        public List<RegistrationAttributes> registrationAttributes;

        
    }
    public class RegistrationAttributes {
        public String name;
        public String value;
    }
}
=========================================================
here is the test class for this one : 
=========================================================
@isTest(seeAllData=false)
public class IDMSIFWUserMappingTest {
    @testSetup
    static void createData(){
        Id profileId3 =  [select id from profile where name=:Label.CLR218IDMS003].id;
        Id roleId1 = label.CLDEC13SLS41;
        User ownUser = new User(alias = 'userpass', 
                                    email='manoj00.1234@accenture.com', isActive=true,
                                     emailencodingkey='UTF-8', lastname='Testing',firstName='testing',
                                     languagelocalekey='en_US',localesidkey='en_US', 
                                     profileid = profileId3, 
                                     timezonesidkey='Europe/London', username='testUser26062018@cts.com',
                                     Company_Postal_Code__c='12345',Company_Phone_Number__c='9986995000',
                                     FederationIdentifier ='manoj0001',IDMS_Registration_Source__c = 'Test',
                                     IDMS_User_Context__c = 'Home',IDMS_PreferredLanguage__c= 'en',
                                     IDMS_county__c = 'test',IDMS_Email_opt_in__c = 'Y',
                                     IDMS_POBox__c = '1111',IsIDMSUser__c = true,IDMSUserWithoutPwd_c__c = true,
                                     IDMSPinVerification__c='123456',IDMSNewPhone__c='99999999',useRroleid =roleId1); 
        try{
            insert ownUser;
        }catch(Exception e){
            system.debug('Exception occured - StackTraceString -->'+e.getStackTraceString());
            system.debug('Exception occured - Message -->'+e.getMessage());
        }
    }
    
    public static testMethod void userMappingTest(){
        user user1 = [select id, username,email,MobilePhone,FirstName,LastName,Country,IDMS_PreferredLanguage__c,
                      DefaultCurrencyIsoCode,Street,City,PostalCode,State,IDMS_County__c,IDMS_POBox__c,
                      IDMS_AdditionalAddress__c,IDMSMiddleName__c,IDMSSalutation__c,Fax,BFO_ACCOUNT_ID__c,
                      IDMS_User_Context__c,IDMS_Registration_Source__c,IDMS_Email_opt_in__c,
                      IDMSHashedToken__c,IDMS_Federated_Id__c,IDMSCompanyFederationIdentifier__c,
                      CompanyName,Company_Address1__c,Company_City__c,Company_Postal_Code__c,Company_Country__c,
                      Company_State__c,IDMSCompanyPoBox__c,IDMSCompanyCounty__c,Company_Address2__c,
                      IDMSClassLevel1__c,IDMSClassLevel2__c,IDMSMarketSegment__c,IDMSMarketSubSegment__c,
                      IDMSCompanyMarketServed__c,IDMSCompanyNbrEmployees__c,IDMSCompanyHeadquarters__c,
                      IDMSAnnualRevenue__c,IDMSTaxIdentificationNumber__c,Company_Website__c,Job_Title__c,
                      Job_Function__c,Phone,IDMSJobDescription__c,IDMS_Profile_update_source__c,Channel__c,SubChannel__c,
                      IDMSPrimaryContact__c,ContactId, FederationIdentifier, IDMSWorkPhone__c,RegistrationAttributes__c from 
                      user where username ='testUser26062018@cts.com'];
        if(user1 != null){
            IDMSIFWUserMapping.userMapping(user1);
        }else{
            Id profileId3 =  [select id from profile where name=:Label.CLR218IDMS004].id;
            User ownUser11 = new User(alias = 'userpas1', 
                                    email='gc050710016@mailinator.com', isActive=true,
                                     emailencodingkey='UTF-8', lastname='Testing',firstName='testing',
                                     languagelocalekey='en_US',localesidkey='en_US', 
                                     profileid = profileId3, 
                                     timezonesidkey='Europe/London', username='testUser05072018@cts.com',
                                     Company_Postal_Code__c='12345',Company_Phone_Number__c='9986995000',
                                     FederationIdentifier ='gc0001',IDMS_Registration_Source__c = 'Test',
                                     IDMS_User_Context__c = 'Home',IDMS_PreferredLanguage__c= 'en',
                                     IDMS_county__c = 'test',IDMS_Email_opt_in__c = 'Y',
                                     IDMS_POBox__c = '1111',IsIDMSUser__c = true,IDMSUserWithoutPwd_c__c = true,
                                     IDMSPinVerification__c='123456',IDMSNewPhone__c='99999999'/*,useRroleid =roleId1*/);
            IDMSIFWUserMapping.userMapping(ownUser11);
        }
        
    }
}

I have impletemened account insert page, with custom controller. 
Here is the code for custom controller : 

public class AccountInsertPageCustomCtrl {
    public Account acc{get; set;}
    
    public  AccountInsertPageCustomCtrl(){
        acc = new Account();
    }
    
    public PageReference Save(){
        if(acc != null){
            insert acc;
        }
        PageReference pg = new PageReference('/'+acc.Id);
        pg.setRedirect(true);
        return pg;
    }
    public PageReference SaveAndNew(){
        if(acc != null){
            insert acc;
        }
        PageReference pg = new PageReference('/001/e?retURL=%2F0016F00002CaaO4');
        pg.setRedirect(true);
        return pg;
    }
    public PageReference Cancel(){
        
        //PageReference pg = new PageReference('/001/o');
        //pg.setRedirect(true);
        return null;
    }
}

Scenario : when I open the VF Enter the required fields, and without clicking on Save and Save&New button, if I click on Cancel, its working fine. as per I have mentioned in the code. but when I do not enter anything, its showing me validation error for Account name ? how can I make it work? I mean, on clicking on Cancel, it must redirect to the All accounts page. 

I have impletemened account insert page, with custom controller. 
Here is the code for custom controller : 

public class AccountInsertPageCustomCtrl {
    public Account acc{get; set;}
    
    public  AccountInsertPageCustomCtrl(){
        acc = new Account();
    }
    
    public PageReference Save(){
        if(acc != null){
            insert acc;
        }
        PageReference pg = new PageReference('/'+acc.Id);
        pg.setRedirect(true);
        return pg;
    }
    public PageReference SaveAndNew(){
        if(acc != null){
            insert acc;
        }
        PageReference pg = new PageReference('/001/e?retURL=%2F0016F00002CaaO4');
        pg.setRedirect(true);
        return pg;
    }
    public PageReference Cancel(){
        
        //PageReference pg = new PageReference('/001/o');
        //pg.setRedirect(true);
        return null;
    }
}

Scenario : when I open the VF Enter the required fields, and without clicking on Save and Save&New button, if I click on Cancel, its working fine. as per I have mentioned in the code. but when I do not enter anything, its showing me validation error for Account name ? how can I make it work? I mean, on clicking on Cancel, it must redirect to the All accounts page.