Webflux Webclient escape slash in URL

Question

I need to include a slash in an URL to access RabbitMQ API and I'm trying to fetch data using WebClient:

WebClient.builder()
     .baseUrl("https://RABBIT_HOSTNAME/api/queues/%2F/QUEUE_NAME")
     .build()
     .get().exchange();

When I replace / with %2F I can see in the request descriptor that %2F has been changed to %252F and because of it I'm getting not found response.

I've tried the following options:

• "\\/" - WebClient changes to %5C but Rabbit doesn't interpret it correctly and returns 404.

• "%5C" - WebClient changes to %255C, Rabbit returns 404.

How can I persist %2F in an url using WebClient?

Answer 1

By default it will always encode the URL, so I can see two options

1. Completely ignore the baseUrl method and pass a fully qualified URL into the uri method which will override the baseUrl method.

   WebClient.builder()
        .build()
        .uri(URI.create( "https://RABBIT_HOSTNAME/api/queues/%2F/QUEUE_NAME"))
        .get().exchange();
   

2. Create your own custom UriBuilderFactory, map a Uri, and set the encoding to NONE

   public class CustomUriBuilderFactory extends DefaultUriBuilderFactory {
   
       public CustomUriBuilderFactory(String baseUriTemplate) {
           super(UriComponentsBuilder.fromHttpUrl(baseUriTemplate));
           super.setEncodingMode(EncodingMode.NONE);
       }
   }
   

   and then you can use uriBuilderFactory of baseUrl, which will allow you to still use uri for just the uri part

   WebClient.builder()
           .uriBuilderFactory(
               new CustomUriBuilderFactory(
                   "https://RABBIT_HOSTNAME/api/queues/%2F/QUEUE_NAME"
           ))
           .build()
           .get()
           .uri(whatever)
           .exchange();
   

Answer 2

You can implement this:

URI uri = URI.create("%2F");

And:

WebClient.builder()
        .baseUrl("https://RABBIT_HOSTNAME/api/queues")
        .build()
        .post()
        .uri(uriBuilder -> uriBuilder.pathSegment(uri.getPath(), "QUEUE_NAME").build())...