OPTIONS HTTP method instead of GET

I am new to ember js. From a route I am using this line this.get('store').findAll('users'); Instead of setting HTTP method GET, it is setting HTTP method OPTIONS.

Because of server is getting OPTIONS HTTP method, server side i am getting error.

io.katharsis.errorhandling.exception.MethodNotFoundException: OPTIONS: /users/

and in browser I am getting this error Request header field Access-Control-Allow-Origin is not allowed by Access-Control-Allow-Headers in preflight response. I am having the below code in application adapter and @CrossOrigin(origins="*") on Spring Rest API side.

import DS from 'ember-data';

export default DS.JSONAPIAdapter.extend({

init() {
    this._super(...arguments);

    this.set('headers', {
      'Access-Control-Allow-Origin': '*'
    });
  },

  host: 'http://localhost:8082',
  namespace: 'spring-katharsis'
});

If the request contain HTTP method GET, I think it may solve the issue.

Please help on this.