如何从HttpClient响应中访问标头？ （角/离子） [英] How to access headers from a HttpClient response? (Angular / Ionic)

问题描述

我正在使用一个返回持票人令牌作为响应标头的登录端点，正如我在网络Chrome检查窗口中看到的那样：

I'm using a login endpoint that returns a bearer token as a response header, as I can see in the "Network" Chrome inspect window:

Response Headers
Access-Control-Allow-Credentials:true
Access-Control-Allow-Origin:http://localhost:8100
Authorization:Bearer eyJhbGciOiJIUzUxMiJ9.eyJzdWIiOiJuZWxpby5jdXJzb3NAZ21haWwuY29tIiwiZXhwIjoxNTEyNzA3OTQ3fQ.pOR4WrqkaFXdwbeod1tNlDniFZXTeMXzKz9uU68rLXEWDAVRgWIphvx5F_VCsXDwimD8Q04JrxelkNgZMzBgXA
Cache-Control:no-cache, no-store, max-age=0, must-revalidate
Content-Length:188
(etc...)

然而，当我尝试使用HttpClient实例从响应中打印headers时：

However, when I try to print "headers" from the response using a HttpClient instance:

  authenticate(credentials) {
    let creds = JSON.stringify(credentials);
    let contentHeader = new HttpHeaders({"Content-Type": "application/json"});
    this.http.post(this.LOGIN_URL, creds, { headers: contentHeader, observe: 'response'})
      .subscribe(
        (resp) => {
          console.log("resp-ok");
          console.log(resp.headers);
        },
        (resp) => {
          console.log("resp-error");
          console.log(resp);
        }
      );
  }

我得到一个完全不同的结构：

I get a completely different structure:

HttpHeaders {normalizedNames: Map(0), lazyUpdate: null, lazyInit: ƒ}
lazyInit : ƒ ()
lazyUpdate : null
normalizedNames : Map(0) {}

我还尝试了get（headerName）方法并获得了空值。我错过了什么？如何从我的回复中获得授权标题？

I also tried the get(headerName) method and got null. What am I missing? How can I get that "Authorization" header from my response?

推荐答案

您确定要将其作为其中的一部分添加吗？响应？您需要在响应中添加标题：

Are you sure you are adding it as a part of the response? You need to add the header in the response:

public void methodJava(HttpServletResponse response){
  ...
 response.addHeader("access-control-expose-headers", "Authorization");
}

然后你可以做你一直在尝试的事情。我认为headers.get（'Authorization'）应该给你想要的值

And then you can do what you have been trying. I think headers.get('Authorization') should give you the desired value

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