How to POST form-url-encoded data with Spring Cloud Feign

Full Java code with a simplified version of kazuar solution, works with Spring Boot:

import java.util.Map;
import feign.codec.Encoder;
import feign.form.spring.SpringFormEncoder;
import org.springframework.beans.factory.ObjectFactory;
import org.springframework.boot.autoconfigure.http.HttpMessageConverters;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.cloud.openfeign.support.SpringEncoder;
import org.springframework.context.annotation.Bean;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import static org.springframework.http.MediaType.APPLICATION_FORM_URLENCODED_VALUE;

@FeignClient(name = "srv", url = "http://s.com")
public interface Client {

    @PostMapping(value = "/form", consumes = APPLICATION_FORM_URLENCODED_VALUE)
    void login(@RequestBody Map<String, ?> form);

    class Configuration {
        @Bean
        Encoder feignFormEncoder(ObjectFactory<HttpMessageConverters> converters) {
            return new SpringFormEncoder(new SpringEncoder(converters));
        }
    }
}

Dependency:

<dependency>
   <groupId>org.springframework.cloud</groupId>
   <artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>

Use FormEncoder for Feign:

• https://github.com/OpenFeign/feign-form

And your Feign configuration can look like this:

class CoreFeignConfiguration {
  @Autowired
  private ObjectFactory<HttpMessageConverters> messageConverters

  @Bean
  @Primary
  @Scope(SCOPE_PROTOTYPE)
  Encoder feignFormEncoder() {
      new FormEncoder(new SpringEncoder(this.messageConverters))
  }
}

Then, the client can be mapped like this:

@FeignClient(name = 'client', url = 'localhost:9080', path ='/rest',
    configuration = CoreFeignConfiguration)
interface CoreClient {
    @RequestMapping(value = '/business', method = POST, 
                 consumes = MediaType.APPLICATION_FORM_URLENCODED)
    @Headers('Content-Type: application/x-www-form-urlencoded')
    void activate(Map<String, ?> formParams)
}