OPTIONS friendly AuthorizationServerEndpointsConfiguration

AuthServerConfig.java

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.context.annotation.Primary;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpMethod;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.oauth2.config.annotation.configuration.ClientDetailsServiceConfiguration;
import org.springframework.security.oauth2.config.annotation.web.configuration.AuthorizationServerEndpointsConfiguration;
import org.springframework.security.oauth2.config.annotation.web.configuration.AuthorizationServerSecurityConfiguration;

@Order(0)
@Configuration
@Import({ ClientDetailsServiceConfiguration.class, AuthorizationServerEndpointsConfiguration.class })
public class AuthServerConfig extends AuthorizationServerSecurityConfiguration {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.authorizeRequests().antMatchers(HttpMethod.OPTIONS, "/oauth/token").permitAll();
        super.configure(http);
    }
}