404 for OPTIONS method in Google AppEngine with Java and Angular.js

Question

I am using Angular.js with AppEngine on Java.
For every HTTP request, Angular.js issues an OPTIONS request before actual request, which returns an HTTP 404 error for me.
Can anybody please tell me why?

In AppEngine how to enable the configuration for OPTIONS method?

edit: I created a filter to handle OPTIONS request. Now I add the Allow header with GET, POST, DELETE, PUT, OPTIONS, HEAD as value and respond with status code 200. But still it shows 404.

it depends on your server side framework. which do you use? and it's not simply "enable", you have to write an handler for such request. could be a plain servlet though — Igor Artamonov, Jan 11 '16 at 05:33
Now, I am responding 200 OK with headers set as Allow:GET, POST, DELETE, PUT, OPTIONS, HEAD. still it shows 404 — Harikrishnan, Jan 11 '16 at 05:54
please show your code. also, servlets better suits this task — Igor Artamonov, Jan 11 '16 at 06:04

Harikrishnan · Accepted Answer · 2016-01-11T06:31:02.213

1

Finally got it working. I wrote the code like this:

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    HttpServletResponse resp = (HttpServletResponse) response;
    HttpServletRequest req = (HttpServletRequest) request;
    resp.setHeader("Cache-Control", "max-age=3600");
    resp.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
    resp.setHeader("Access-Control-Allow-Methods", "POST, GET, PUT, DELETE, OPTIONS");
    resp.setHeader("Access-Control-Allow-Origin", "www.myapp.com");
    resp.setHeader("Access-Control-Allow-Credentials", "true");
    if (req.getMethod().equals("OPTIONS")) { 
        resp.flushBuffer();
    } else {
        chain.doFilter(request, resp);
    }
}

I just wrote the resp.setHeader("Access-Control-Allow-Origin", "*"); before. After writing the whole headers, it started working.

edited Jan 11 '16 at 06:31

answered Jan 11 '16 at 06:07

Harikrishnan

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`resp.setHeader("Access-Control-Allow-Origin", "*")` doesn't change server behavior for 404. and you don't need to put CORS headers for anything except OPTION. also '*' origin is insecure – Igor Artamonov Jan 11 '16 at 06:19
Thank you for your suggestion. I will change it. – Harikrishnan Jan 11 '16 at 06:30
Thank you, this saved us loads of time ! – Deepan Prabhu Babu Aug 23 '18 at 02:07

404 for OPTIONS method in Google AppEngine with Java and Angular.js

1 Answers1