Problems with Headers

Ionic Framework ionic-v3
1

I have the following error:
If anyone can help me thank you!
I’m sorry for my english but I’m writing for the translator

Argument of type ‘{ headers: Headers; }’ is not assignable to parameter of type ‘{ headers?: HttpHeaders | { [header: string]: string | string[]; }; observe?: “body”; params?: Ht…’.
Types of property ‘headers’ are incompatible.
Type ‘Headers’ is not assignable to type ‘HttpHeaders | { [header: string]: string | string[]; }’.
Type ‘Headers’ is not assignable to type ‘{ [header: string]: string | string[]; }’.
Index signature is missing in type ‘Headers’.

my code

import { HttpClient } from '@angular/common/http';
import { Response, ResponseOptions, Http, Headers} from '@angular/http';
import { Injectable } from '@angular/core';
import 'rxjs/add/operator/map';

@Injectable()
export class ServiceProvider {
  api: string = 'http://localhost:8080/api/';

  constructor(public http: HttpClient) {

  }
    getData(){
      let headers = new Headers();
    headers.append('Content-Type', 'application/json');
      return this.http.get(this.api + 'apiRecupera.php').map(res => res )
    }

    postData(parans){
        let headers = new Headers({'Content-Type' : 'application/x-www-form-urlencoded' });
        return this.http.post(this.api + "apiCadastro.php", parans, {
          headers : headers,
        }).map(res => res )
    }

}