Angular 5 Http 拦截器未检测到响应标头 (POST)

Question

当我控制台记录它时，我无法在拦截器中获取自定义响应标头。

''控制台日志响应''

HttpResponse { 标头：HttpHeaders，状态：200，statusText：“确定”，确定：true，... }

HttpHeaders 惰性初始化 : ▪ () 惰性更新 : 无效的 规范化名称 : 地图(0) {} 原型 : 目的 好的 : 真的 地位 : 200 状态文本 : “好的” 类型 : 4

我们还在服务器端添加了 Access-control-expose-header。我仍然没有得到答复。不确定我是否错过了拦截器方法中的某些内容。

拦截器方法

intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        req = req.clone({
            setHeaders: {
                'Accept': 'application/vnd.employee.tonguestun.com; version=1',
                'Content-Type': 'application/json',
            }
        });

    return next.handle(req)
        .do((ev: HttpEvent<any>) => {
            console.log(ev)
            if (ev instanceof HttpResponse) {
                console.log(ev.headers);
            }
            // return ev;
        })

}

网络选项卡中的自定义标头

访问控制允许凭据：true

访问控制允许方法：GET、POST、OPTIONS

访问控制允许来源：*

访问控制公开标头：访问令牌，客户端，到期，令牌类型，uid

访问令牌：haIXZmNWSdKJqN2by7JH1g

缓存控制：max-age=0，私有，必须重新验证

客户端：j_2dxD7NVMjGeX8BbBuELA

内容类型：application/json；字符集=utf-8

有效期：1525931943

这也是我的服务呼叫，也在呼叫中添加了观察“响应”。

服务电话

return this.http.post(`${environment.baseUrl}${environment.signup}`, data, {observe: "response"})
  .map(response => response);

AppModule.ts

import { BrowserModule } from '@angular/platform-browser';
   import { NgModule } from '@angular/core';
   import { CommonModule } from '@angular/common';

   import { AppComponent } from './app.component';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { HttpClientModule } from '@angular/common/http';
import { HTTP_INTERCEPTORS } from '@angular/common/http';
import { AppInterceptor } from './services/app-interceptor.service';

import { HomeModule } from './home/home.module'; 
import { SharedModule } from './shared/shared.module';
import { AppRoutingModule } from './app-routing.module';
import { AuthService } from './services/auth.service';
import { AuthGuardService } from './services/auth-guard.service';
import { FormsModule, ReactiveFormsModule } from '@angular/forms';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    FormsModule,
    ReactiveFormsModule,
    CommonModule,
    HttpClientModule,
    BrowserAnimationsModule,
    HomeModule,
    SharedModule,
    AppRoutingModule,
  ],
  providers: [
    AuthService,
    AuthGuardService,
    {
      provide: HTTP_INTERCEPTORS,
      useClass: AppInterceptor,
      multi: true
    },
  ],
  bootstrap: [AppComponent]
})
export class AppModule { }

请帮助我。预先感谢！

Answer 1

HttpInterceptor的这个实现应该对你有帮助。 HttpResponse 类有一个 Headers 属性，它将帮助您读取响应标头。

Answer 2

我也遇到过同样的问题。如果您通过

http

调用您的服务，它将不起作用，因为拦截器不熟悉它，请使用

httpClient

然后拦截器会自动检测您的每个请求，并且拦截器还会将您的标头发送到服务器端

AppHttpInterceptor.ts

    import { Injectable } from "@angular/core";
    import {
        HttpInterceptor,
        HttpRequest,
        HttpResponse,
        HttpErrorResponse,
        HttpHandler,
        HttpEvent
    } from '@angular/common/http';

    import { Observable } from 'rxjs/Observable';
    import 'rxjs/add/operator/do';
    import 'rxjs/add/operator/catch';
    import 'rxjs/add/observable/throw';
    import { Http, Response, RequestOptions, Headers } from '@angular/http';
    import { Router } from '@angular/router'


    @Injectable()
    export class AppHttpInterceptor implements HttpInterceptor {
        constructor(private router: Router){

        }
        headers = new Headers({
            'Content-Type': 'application/json',
            'Token': localStorage.getItem("Token")
        });
        intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {

            console.log("intercepted request ... ");

            // Clone the request to add the new header.
            const authReq = req.clone({ headers: req.headers.set("Token", localStorage.getItem("Token")) });

            console.log("Sending request with new header now ...");

            //send the newly created request
            return next.handle(authReq)
                .catch(err => {
                    // onError
                    console.log(err);
                    if (err instanceof HttpErrorResponse) {
                        console.log(err.status);
                        console.log(err.statusText);
                        if (err.status === 401) {
                            window.location.href = "/login";
                        }
                    }
                    return Observable.throw(err);
                }) as any;
        }
    }

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { HttpModule } from '@angular/http';
import { HttpClient } from "@angular/common/http";
import { FormsModule } from '@angular/forms';
import { ToasterModule, ToasterService } from "angular2-toaster";
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { RouterModule } from '@angular/router';
import { ReactiveFormsModule } from '@angular/forms';
import { HttpClientModule,HTTP_INTERCEPTORS} from '@angular/common/http';
import {AppHttpInterceptor} from './Common/AuthInterceptor';
import { AppRoutes } from '../app/Common/Routes';
import { AppComponent } from './app.component';

@NgModule({
  declarations: [
    AppComponent,
  ],
  imports: [
    BrowserModule, HttpModule,HttpClientModule, ReactiveFormsModule, FormsModule, BrowserAnimationsModule, RouterModule.forRoot(AppRoutes)
  ],
  providers: [
    {
      provide: HTTP_INTERCEPTORS,
      useClass: AppHttpInterceptor,
      multi: true
    }
  ],
  bootstrap: [AppComponent]
})
export class AppModule { 
  constructor(private httpClient: HttpClient){
    this.httpClient.get("https://jsonplaceholder.typicode.com/users").subscribe(
      success => {
        console.log("Successfully Completed");
        console.log(success);
      }
    );
  }
}

Answer 3

这个 Stack Overflow 答案帮助我们解决了这个问题。问题出在 nginx 配置上。我们错过了 access-control-expose-header 中的always关键字。

Answer 4

headers 映射是延迟加载的，因此需要触发映射加载内容才能列出 headers，例如调用 headers.keys() 或通过 key headers.get('name-of-key ').

Answer 5

来自文档https://angular.io/guide/http#intercepting-requests-and-responses

const authReq = req.clone({
      headers: req.headers.set('Authorization', authToken)
    });

    // send cloned request with header to the next handler.
    return next.handle(authReq);

查看使用新变量，了解如何使用 set over req.headers 来更改标头