serviceRead.ts

@Injectable()
export class UserService {
    
    constructor(private http: Http) { 
    }

    getUsers(searchCriteria:any) : Observable<User[]>{
        let params: URLSearchParams = new URLSearchParams();
        params.set('name', searchCriteria);

        return this.http.get("http://localhost:3000/getUsers", { search: params })
                .map((res:any) => {
                    return res.json();
                })
                .catch((error:any) => {
                    return Observable.throw(error.json ? error.json().error : error || 'Server error')
                }); 
    }
}