Building Angular services for RESTful integration

In this section, you will learn about different ways in which Angular components can communicate with server APIs, such as Spring RESTful APIs:

• Invoking server APIs using the Angular HTTP service
• Invoking server APIs using the Angular HtClient service

Invoking server APIs using the Angular HTTP service

In this section, you will learn about some of the key aspects related with usage of the Angular HTTP service APIs for having Angular app communicate with server APIs such as Spring RESTful APIs. Note, the HTTP service is part of HttpModule:

1. Create a data service: Create a class, namely, DoctorService in a file, namely, doctor.service.ts and annotate it with @Injectable. 
2. Inject the HTTP service in the constructor of this service class. The following is the sample code:

        import { Injectable } from '@angular/core';
        import { Http } from '@angular/http';

        @Injectable()
        export class DoctorService {
          //
         ...