angular - 从Angular 2/4中的正常函数处理错误

Question

我使用代码来验证jwt中的是否过期(来自angular2-jwt)。
但是，如果用户更改localStorage中token的值，例如:
id_token =>“123”，它显示错误并停止应用。
但是，我想在Guard中处理此错误。

//错误:

core.es5.js:1020 ERROR Error: Uncaught (in promise): Error: JWT must have 3 parts
Error: JWT must have 3 parts

如果引发了 throw ，如何在Guard中处理此错误？

//Guard.ts:

 canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean>|boolean
 {

          if (this.tokenService.isTokenExpired(token)) {
              this.auth.loggedIn = false;
              this.loginService.logout();
              this.notifications.success = false;
              this.notifications.status = 401;
              this.notifications.state = 'alertFail';
              this.notifications.message = 'Token Expirado! Faça o login novamente.';
              this.notifications.arrayError = [];
              this.notifications2.setNotifications(this.notifications);
              this.router.navigate(['/login']);
              return false;
          }

      return true;
      }

//其中一个功能:

public decodeToken(token: string): any {
        let parts = token.split('.');

        if (parts.length !== 3) {
            throw new Error('JWT must have 3 parts');
        }

        let decoded = this.urlBase64Decode(parts[1]);
        if (!decoded) {
            throw new Error('Cannot decode the token');
        }

        return JSON.parse(decoded);
    }

Answer 1

try/catch块是您要执行的操作:

    canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean>|boolean
     {
         try {
              if (this.tokenService.isTokenExpired(token)) {
                  this.auth.loggedIn = false;
                  this.loginService.logout();
                  this.notifications.success = false;
                  this.notifications.status = 401;
                  this.notifications.state = 'alertFail';
                  this.notifications.message = 'Token Expirado! Faça o login novamente.';
                  this.notifications.arrayError = [];
                  this.notifications2.setNotifications(this.notifications);
                  this.router.navigate(['/login']);
                  return false;
              }
            }
          catch (e) {
             return false;
          }
          return true;
 }