Angular $http status (-1)

问题:

I call a backend service/resource by AngularJs $HTTP GET. When it is not available it returns 404 and Chrome Network tab shows that it is 404 as the followings:

Request Method:OPTIONS
Status Code:404 Not Found

BUT inside AngularJs $HTTP call result, I get status=-1 and not 404:

{data: null, status: -1, config: Object, statusText: ""}

Why does it happen?

NB ) I have a jetty Service on the backend and enabled CORS:

"Access-Control-Allow-Origin":"*"
"Access-Control-Allow-Headers": "origin, content-type, accept, authorization"
"Access-Control-Allow-Methods": "GET, POST, PUT, DELETE, OPTIONS, HEAD"

回答1:

It returns -1 because, as the traces show, the GET request has not even been sent. What has been sent is the pre-flight OPTIONS request, which, by returning 404, prevented the browser to send the actual GET request.

Your server shouldn't return a 404 response for the OPTIONS request. It should return a 200 response.