How to set base url and query parameters for WebClient? - spring

Question

In my service, I have to get response from some different urls with parameters.
get from http://a.com:8080/path1?param1=v1
get from http://b.com:8080/path2?param2=v2
get from http://c.com:8080/path3?param3=v3
I am using WebClient to do the job as following.
public class WebClientTest {
private WebClient webClient = WebClient.builder().build();
#Test
public void webClientTest() {
Mono<String> a = webClient.get()
.uri(uriBuilder -> uriBuilder.scheme("http").host("a.com").port(8080).path("/path1")
.queryParam("param1", "v1")
.build())
.retrieve()
.bodyToMono(String.class);
Mono<String> b = webClient.get()
.uri(uriBuilder -> uriBuilder.scheme("http").host("b.com").port(8080).path("/path2")
.queryParam("param2", "v2")
.build())
.retrieve()
.bodyToMono(String.class);
Mono<String> c = webClient.get()
.uri(uriBuilder -> uriBuilder.scheme("http").host("c.com").port(8080).path("/path3")
.queryParam("param3", "v3")
.build())
.retrieve()
.bodyToMono(String.class);
//zip the result
}
}
As you can see, I have to set scheme, host, port separately again and again.
So my questions are:
1. Am I using WebClient in a right way?
2. Is it possible to set scheme, host, port in a method together? I know that webClient.get().uri("http://a.com:8080/path1?param1=v1").retrieve() works, but what I am expecting is something like:
webClient.get()
.uri(uriBuilder -> uriBuilder/*.url("http://a.com:8080/path1")*/
.queryParam("param1", "v1")
.build())
.retrieve()
.bodyToMono(String.class);

Answer 1

As of Spring Framework 5.2, there is an additional method that can help with your specific situation:
Mono<String> response = this.webClient
.get()
.uri("http://a.com:8080/path1", uri -> uri.queryParam("param1", "v1").build())
.retrieve()
.bodyToMono(String.class);
I wouldn't advise creating one WebClient per host as a general rule. It really depends on your use case. Here it seems your client might send requests to many hosts, and creating many HTTP clients can be a bit wasteful here.

Answer 2

The way I solved this was to have a WebClient for each different url.
So you would have
private WebClient aClient = WebClient.create("a.com")
private WebClient bClient = WebClient.create("b.com")
private WebClient cClient = WebClient.create("c.com")
Then interact with each WebClient depending on what you're calling.
https://docs.spring.io/spring/docs/5.0.7.RELEASE/spring-framework-reference/web-reactive.html#webflux-client-retrieve