How to get file passed from post request in camel?

Question

I have the following code:

import org.apache.camel.Exchange;
import org.apache.camel.Processor;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.component.restlet.RestletComponent;
import org.restlet.ext.spring.SpringServerServlet; 
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

import java.io.FileOutputStream;
import java.io.InputStream;
import java.util.Map;
import java.util.HashMap;

@Component
public class DummyRoute extends RouteBuilder {
    @Override
    public void configure() throws Exception {

        rest("/upload").post().to("file://rest_files");
    }

    @Bean
    public ServletRegistrationBean servletRegistrationBean() {
        SpringServerServlet serverServlet = new SpringServerServlet();
        ServletRegistrationBean regBean = new ServletRegistrationBean( serverServlet, "/rest/*");
        Map<String,String> params = new HashMap<>();
        params.put("org.restlet.component", "restletComponent");
        regBean.setInitParameters(params);
        return regBean;
    }


    @Bean
    public org.restlet.Component restletComponent() {
        return new org.restlet.Component();
    }

    @Bean
    public RestletComponent restletComponentService() {
        return new RestletComponent(restletComponent());
    }

}

I load file using postman and app stores file inside the folder rest_files

But content of file and its name looks strange.

file name: ID-username-1508923387747-0-2
content:

How to make it to store at least correct content?