Angular 7 HttpClient发布响应标头为空

Question

我正在尝试从具有Spring安全后端的Angular 7执行登录：

login(username: string, password: string) {

    const formData = new FormData();
    formData.append('username', username);
    formData.append('password', password);

    return this.http.post<UserInfo>(`${API_URL}/login`, formData, {observe: 'response'})
      .pipe(map(response => {

        const jwtToken = response.headers.get(AUTHORIZATION).replace('Bearer', '').trim();
        const userInfo = response.body;

        if (jwtToken && userInfo) {
          const user = new User(username, password, jwtToken, userInfo);
          localStorage.setItem(CURRENT_USER, JSON.stringify(user));
          this.currentUserSubject.next(user);
        }

        return response;
      }));
  }

但是，response.headers只是空的，不包含任何标题。 Postman和Chrome开发人员工具显示了许多标头，甚至是我需要的标头-授权。我已经审查了许多SO问题和github问题，但是他们都说相同的话，这对我不起作用-只是在CORS Access-Control-Expose-Headers中列出了头，但是我做到了，没有任何改变。这是相关的Spring配置：

@Bean
    public CorsConfigurationSource corsConfigurationSource() {
        CorsConfiguration configuration = new CorsConfiguration();
        configuration.addAllowedOrigin("http://localhost:4200");
        configuration.addExposedHeader("Authorization");
        configuration.addAllowedMethod("*");
        configuration.addAllowedHeader("*");
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", configuration);
        return source;
    }

在这一点上，我陷入困境，不知道如何使Angular访问这些标头：

Answer 1

您需要authorization header，可以通过response.headers.get("Authorization")获得。试试：

const jwtToken = response.headers.get("Authorization").replace('Bearer', '').trim();

Answer 2

在服务器端，您需要配置“ Access-Control-Allow-Headers”。请参阅这篇文章：Angular 6 Get response headers with httpclient issue。

对我来说，这种配置可以达到目的：

@Bean
CorsConfigurationSource corsConfigurationSource() {
    final UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
    CorsConfiguration config = new CorsConfiguration();
    config.setAllowCredentials(true);
    config.addAllowedOrigin("*");
    config.addExposedHeader(
            "Authorization, x-xsrf-token, Access-Control-Allow-Headers, Origin, Accept, X-Requested-With, "
                    + "Content-Type, Access-Control-Request-Method, Custom-Filter-Header");
    config.addAllowedHeader("*");
    config.addAllowedMethod("OPTIONS");
    config.addAllowedMethod("GET");
    config.addAllowedMethod("POST");
    config.addAllowedMethod("PUT");
    config.addAllowedMethod("DELETE");
    source.registerCorsConfiguration("/**", config);
    return source;
}