constructor(private http: HttpClient) {
    http.get('http://localhost:8080/resource').subscribe(data => this.greeting = data);
}

@RequestMapping("/resource")
    public Map<String,Object> home() {
        Map<String,Object> model = new HashMap<String,Object>();
        model.put("id", UUID.randomUUID().toString());
        model.put("content", "Hello World");
        return model;
}

response.setHeader("Access-Control-Allow-Origin", "*");
response.setHeader("Access-Control-Allow-Methods", "POST, PUT, GET, OPTIONS, DELETE");