Die Eigenschaft 'http' ist für den Typ 'Component', Angular 2 nicht vorhanden

Ich bin neu in angle2 und TypeScript und habe bereits einen halben Tag damit verbracht, mit ng2-Formularen herauszufinden. Ich habe alle meine Routen fertiggestellt und alle erforderlichen Formulare erstellt. Derzeit versuche ich zu verstehen, wie man in angle2 mit TypeScript postet 

Das ist mein Fehler:

ERROR in [default] simpleapp/src/app/clients/add-client/add-client.component.ts: 52: 16 Die Eigenschaft 'http' ist für den Typ 'AddClientComponent' nicht vorhanden.

Und ich kann nicht finden, woher dieses Problem kommt. Ich habe angular/http in meine Komponente importiert. Ich habe den Header und die Antwort angegeben, wie das offizielle Tutorial sagt, aber ich kann dieses Problem trotzdem sehen. Was fehlt mir und wo liegt mein Problem? Danke im Voraus

Dies ist meine Komponente :

import 'rxjs/add/operator/map';

import {Component} from '@angular/core';
import {Http, Response, RequestOptions, Headers} from '@angular/http';

import {Employee} from "./model/add-client.model";

@Component({
  selector: 'app-add-client',
  templateUrl: 'add-client.component.html',
  styleUrls: ['add-client.component.css']
})

export class AddClientComponent {

   departments: Array<any>;
   firstName: '';
   lastName: '';
   id: null;
   salary: null;
   phone: null;
   departmentId: null;

  constructor(http: Http) {
    http.get('api/departments')
      .map((res: Response) => res.json())
      .subscribe((departments: Array<any>) => this.departments = departments);
  }

  model = new Employee(
    this.id,
    this.firstName,
    this.lastName,
    this.salary,
    this.departmentId,
    this.phone
  );

  submitted = false;

  addEmployee = 'api/employees'

  handleError = 'Post Error';

  onSubmit(model) {
    this.submitted = true;

    let body = JSON.stringify({ model });
    let headers = new Headers({ 'Content-Type': 'application/json' });
    let options = new RequestOptions({ headers: headers });

    return this.http.post(this.addEmployee, body, options)
      .catch(this.handleError);

  }
}

Dies ist meine Vorlage :

    <div class="container">
    <md-card class="demo-card demo-basic">
      <md-card-title color="primary back-header">Employee Form</md-card-title>
      <md-card-content>
        <form (ngSubmit)="onSubmit(model)" #employeeForm="ngForm">
          <md-toolbar for="firstName">First Name</md-toolbar>
          <md-input
            class="demo-full-width input-text"
            type="text"
            id="firstName"
            required
            [(ngModel)]="model.firstName"
            name="firstName"
            #firstName="ngModel">
          </md-input>

          <md-toolbar for="lastName">Last Name</md-toolbar>
          <md-input
            class="demo-full-width input-text"
            type="text"
            id="lastName"
            required
            [(ngModel)]="model.lastName"
            name="lastName"
            #lastName="ngModel">
          </md-input>

          <md-toolbar for="salary">Salary</md-toolbar>
          <md-input
            class="demo-full-width input-text"
            type="number"
            id="salary"
            placeholder="USD"
            required
            [(ngModel)]="model.salary"
            name="salary"
            #salary="ngModel">
          </md-input>

          <md-toolbar for="departmentId">Department</md-toolbar>
            <select class="demo-full-width option-department input-text"
                    id="departmentId"
                    required
                    [(ngModel)]="model.departmentId"
                    name="departmentId"
                    #departmentId="ngModel">
              <option
                *ngFor="let department of departments"
                [value]="department.id">{{department.name}}
              </option>
            </select>

          <md-toolbar for="phone">Phone</md-toolbar>
          <md-input
            class="demo-full-width input-text"
            type="number"
            id="phone"
            placeholder="phone #"
            required
            [(ngModel)]="model.phone"
            name="phone"
            #phone="ngModel">
          </md-input>

          <button  md-raised-button color="primary"
                   type="submit"
                   class="btn btn-default"
                   [disabled]="!employeeForm.form.valid">Submit
          </button>
        </form>
      </md-card-content>
    </md-card>
  <md-card [hidden]="!submitted">
      <md-card-title>You submitted the following:</md-card-title>
    <md-list>
      <md-list-item>
        <label>First Name:</label> {{model.firstName}}
      </md-list-item>
      <md-list-item>
        <label>Last Name:</label> {{model.lastName}}
      </md-list-item>
      <md-list-item>
        <label>Salary:</label> {{model.salary}}
      </md-list-item>
      <md-list-item>
        <label>Department:</label> {{model.departmentId}}
      </md-list-item>
      <md-list-item>
        <label>Phone:</label> {{model.phone}}
      </md-list-item>
    </md-list>
  </md-card>
</div>

Dies ist mein Modul :

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpModule }    from '@angular/http';


import { MaterialModule } from '@angular/material';
import {MdListModule} from '@angular/material/list';


import { AppComponent } from './app.component';
import { routing, appRoutingProviders }  from './app.routing';

//==============

import { ClientsComponent } from './clients/clients.component';
import { DepartmentsComponent } from './departments/departments.component';
import { AddClientComponent } from './clients/add-client/add-client.component';
import { AddDepartmentComponent } from './departments/add-department/add-department.component';

@NgModule({

  imports: [
    BrowserModule,
    FormsModule,
    HttpModule,
    routing,

    MaterialModule.forRoot(),
    MdListModule.forRoot()
  ],

  declarations: [
    AppComponent,
    ClientsComponent,
    DepartmentsComponent,
    AddClientComponent,
    AddDepartmentComponent
  ],

  providers: [appRoutingProviders],

  bootstrap: [AppComponent]
})
export class AppModule { }