How can I configure Lagom framework to work with CORS?

Question

How can I configure Lagom framework to work with CORS request (method request 'options').

Answer 1

To allow a Lagom service written in Java to work with CORS, you'll need to implement a CORS filter per Play:

package example.service.impl


import play.filters.cors.CORSFilter;
import play.http.DefaultHttpFilters;

import javax.inject.Inject;

// See https://playframework.com/documentation/2.5.x/CorsFilter
public class MyCORSFilter extends DefaultHttpFilters {
    @Inject
    public MyCORSFilter(CORSFilter corsFilter) {
        super(corsFilter);
    }
}

and then in your application.conf, you'll need to add the filter:

play.http.filters = "example.service.impl.MyCORSFilter"

// To properly setup the CORSFilter, please refer to https://playframework.com/documentation/2.5.x/CorsFilter
// This example is only meant to show what's required for Lagom to use CORS.
play.filters.cors {
  // review the values of all these settings to fulfill your needs. These values are not meant for production.
  pathPrefixes = ["/api"]
  allowedOrigins = null
  allowedHttpMethods = null
  allowedHttpHeaders = null
  exposedHeaders = []
  supportsCredentials = false
  preflightMaxAge = 6 hour
}

For more info, see the example CORS service and the Play docs.