NullInjectorError:没有JwtHelperService的提供者

Question

我在Angular 5.

第一: npm install @auth0/angular-jwt --save

然后我导入它: import { JwtHelperService } from '@auth0/angular-jwt';

这是我的身份验证服务:

import { JwtHelperService } from '@auth0/angular-jwt';

@Injectable()
export class AuthService {

  constructor(public jwtHelper: JwtHelperService) { }

  public isAuthenticated(): boolean {
    console.log (localStorage['token']);
    const token = localStorage.getItem('token');
    // Check wheter the token is expired and return true or false
    return !this.jwtHelper.isTokenExpired(token);
  }
}

这是我的警卫服务

export class GuardService implements CanActivate {

  constructor(public auth: AuthService, public router: Router) {}

  canActivate(): boolean {
    if (!this.auth.isAuthenticated()){
        console.log ('bye');
        this.router.navigate(['/login']);
        return false;
    }
    console.log ('Welcome');
    return true;
  }

}

localstorage中有一个令牌:

eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImp0aSI6ImFjMTUyNzZhZjA2MjU1YTdlMDM0MmQ5ODg4N2M1ZmI2ZWNmM2RlNGUyNjhmYTc4MTliODRhOTVmMmJiNGZiMTliMDFkNjBhNWRlNjhlN2VlIn0.eyJhdWQiOiJmMDExY2M1OC00MGNlLTQzYTktOGY3MS04NDI0OTRlM2E5OTciLCJqdGkiOiJhYzE1Mjc2YWYwNjI1NWE3ZTAzNDJkOTg4ODdjNWZiNmVjZjNkZTRlMjY4ZmE3ODE5Yjg0YTk1ZjJiYjRmYjE5YjAxZDYwYTVkZTY4ZTdlZSIsImlhdCI6MTUyMzI5NzkzNSwibmJmIjoxNTIzMjk3OTM1LCJleHAiOjE1MjMyOTgyMzUsInN1YiI6IjIiLCJzY29wZXMiOlsiYXV0aGVudGljYXRlZCIsImFuZ3VkcnUiXX0.RNY2Yb9xiJDcER4rtHEAYMmoLyvPYij-upZc97q-mSgICKE6_xWih_IBjY4cHQXkkiRyCXaqCfwfMM4YWVjv7bsMlLN5bWlH0JTeYoYf2gENLBIG51NwGpU3iAl8KG_51ljZKbs3RE_ULDbphM1NG8BhobVQ5RlObWzejrkPcMHqlGJaMOMLQuXC1iBR2jI9tlfiP4RD4FUUsRkUEUJ5PSIRl34jWoTv31SSf1bkv43q3YeKTfk6pXZ5Ft_eV8G871KkmQSHANAn26A5ujj2FOh-uCV_VNJ97RuTQ6J4NP2YB-mMaWYpZ1xF-4ndqafRGFXJ_8euBO4cA36zvP3B7g

这是错误:

ERROR Error: Uncaught (in promise): Error: StaticInjectorError(AppModule)[AuthService -> JwtHelperService]: 
  StaticInjectorError(Platform: core)[AuthService -> JwtHelperService]: 
    NullInjectorError: No provider for JwtHelperService!
Error: StaticInjectorError(AppModule)[AuthService -> JwtHelperService]: 
  StaticInjectorError(Platform: core)[AuthService -> JwtHelperService]: 
    NullInjectorError: No provider for JwtHelperService!
    at _NullInjector.get (core.js:1002)
    at resolveToken (core.js:1300)
    at tryResolveToken (core.js:1242)
    at StaticInjector.get (core.js:1110)
    at resolveToken (core.js:1300)
    at tryResolveToken (core.js:1242)
    at StaticInjector.get (core.js:1110)
    at resolveNgModuleDep (core.js:10854)
    at _createClass (core.js:10891)
    at _createProviderInstance$1 (core.js:10865)
    at _NullInjector.get (core.js:1002)
    at resolveToken (core.js:1300)
    at tryResolveToken (core.js:1242)
    at StaticInjector.get (core.js:1110)
    at resolveToken (core.js:1300)
    at tryResolveToken (core.js:1242)
    at StaticInjector.get (core.js:1110)
    at resolveNgModuleDep (core.js:10854)
    at _createClass (core.js:10891)
    at _createProviderInstance$1 (core.js:10865)
    at resolvePromise (zone.js:814)
    at resolvePromise (zone.js:771)
    at eval (zone.js:873)
    at ZoneDelegate.invokeTask (zone.js:421)
    at Object.onInvokeTask (core.js:4740)
    at ZoneDelegate.invokeTask (zone.js:420)
    at Zone.runTask (zone.js:188)
    at drainMicroTaskQueue (zone.js:595)

此外,它显示了死记硬背,但没有来自服务的阵列......

任何的想法？

谢谢!

Answer 1

您需要使用JwtModule提供的@auth0/angular-jwt,它将添加JwtHelperService到提供程序,或者您需要手动将其添加到模块提供程序.

就像是

const JWT_Module_Options: JwtModuleOptions = {
    config: {
        tokenGetter: yourTokenGetter,
        whitelistedDomains: yourWhitelistedDomains
    }
};

@NgModule({
    imports: [
        JwtModule.forRoot(JWT_Module_Options)
    ],
...

更多信息请参阅文档

Answer 2

晚会晚了一点，但是我遇到了同样的问题，试图遵循独立的文档，它没有涵盖的是需要导入在服务的构造函数中引用的选项InjectionToken：

import { JwtHelperService, JWT_OPTIONS  } from '@auth0/angular-jwt';

...

providers: [
        { provide: JWT_OPTIONS, useValue: JWT_OPTIONS },
        JwtHelperService
    ]