CORS not working on Chrome

Question

I\'ve set up Cross-Origin Resource Sharing on a server (Jetty using the CrossOriginFilter) and it works perfectly on IE8 and Firefox. On Chrome, it just ... doesn\'t.

Answer 1

In my case, it's localhost:8001 (the front-end) which tries to call the APIs at localhost:7001 (on server.js as a Node server). Even I had the CORS plugin installed and turned on on Chrome, still the CORS policy rejected them as preflight cases.

It took me more than half day to finally resolve the issue. Here are the "stupid" steps, believe it or not:

i. Turn OFF the CORS plugin, reload the app, at this time you should still get the errors which are correct.

ii. Turn it back ON, reload the app, if the APIs are successful, stop here, no need to proceed to iii.

iii. However if you still get the CORS rejection, then uninstall Chrome and install an up-to-date Chrome.

iv. On the new Chrome, the previously installed CORS plugin should still be there but with OFF status.

v. Reload the page, you should get the CORS rejection messages on console which are correct.

vi. Turn it back ON, reload the page, the errors should disappear.

No further ideas if the above steps still do not work in your case.

I also tried the following on server.js (Node) and still do not work, so no bother to try:

var app = express();
var cors = require('cors'); // Already done “npm i cors --save-dev”
app.options('*', cors());