In net core use a service within your own class and call the class using new class()

Question

I have created a class to validate my own token. Within this class I need to use a service, which I have previously added in the startup.cs with services.AddScoped. how can I do it ?

x.SecurityTokenValidators.Add(new DynamicKeyJwtValidationHandler());

Inside the DynamicKeyJwtValidationHandler class I need to use a service.

public class DynamicKeyJwtValidationHandler : JwtSecurityTokenHandler, ISecurityTokenValidator
    {
        public SecurityKey GetKeyForClaimedId(string claimedId)
        {
            throw new NotImplementedException();
        }

        public override ClaimsPrincipal ValidateToken(string token, TokenValidationParameters validationParameters, out SecurityToken validatedToken)
        {
            ClaimsPrincipal cp = new ClaimsPrincipal();
            validatedToken = null;
            try
            {
                cp = base.ValidateToken(token, validationParameters, out validatedToken);
            } catch (Exception) {}

            return cp;
        }
    }

See this answer: https://stackoverflow.com/a/32461714/12431728 — Matt U, Dec 17 '19 at 14:10

Samuel Middendorp · Answer 1 · 2019-12-17T11:18:19.123

1

Use dependency injection in the constructor of the class

public class DynamicKeyJwtValidationHandler : JwtSecurityTokenHandler, ISecurityTokenValidator
    {
        private readonly YourService _service
        public DynamicKeyJwtValidationHandler(YourService service){
             _service = service
        }
        public SecurityKey GetKeyForClaimedId(string claimedId)
        {
            throw new NotImplementedException();
        }

        public override ClaimsPrincipal ValidateToken(string token, TokenValidationParameters validationParameters, out SecurityToken validatedToken)
        {
            ClaimsPrincipal cp = new ClaimsPrincipal();
            validatedToken = null;
            try
            {
                cp = base.ValidateToken(token, validationParameters, out validatedToken);
            } catch (Exception) {}

            return cp;
        }
    }

edited Dec 17 '19 at 11:18

answered Dec 17 '19 at 11:02

Samuel Middendorp

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4
14

no, because then I can't do new DynamicKeyJwtValidationHandler() because constructor expects a service – vidgarga Dec 17 '19 at 11:08
@vidgarga, you should be injecting your DynamicKeyJwtValidationHandler too, and not call its constructor directly using new. So DynamicKeyJwtValidationHandler should be a service too. – Polyfun Dec 17 '19 at 11:18
Like Polyfun said ! However if you do not want to follow trough with this pattern you can just instantiate the service in the validationhandler class or pass it when calling `new DynamicKeyJwtValidationHandler()` . I would highly recommend the proper injecting pattern tho ! – Samuel Middendorp Dec 17 '19 at 11:23
@Polyfun Can you write a little example? – vidgarga Dec 17 '19 at 11:49
@vidgarga As DynamicKeyJwtValidationHandler implements ISecurityTokenValidator, then it should probably be added as a ISecurityTokenValidator service. This post might help https://stackoverflow.com/questions/47138849/how-to-correctly-get-dependent-scoped-services-from-isecuritytokenvalidator. – Polyfun Dec 17 '19 at 13:54

In net core use a service within your own class and call the class using new class()

1 Answers1