SpringWebFlux Transitioning from RestTemplate to WebClient in Spring Boot

GET

Örnek

Şöyle yaparız

RestTemplate restTemplate = new RestTemplate();
ResponseEntity<String> response = restTemplate.getForEntity("http://example.com",
  String.class);


WebClient webClient = WebClient.create();
Mono<String> response = webClient.get()
    .uri("http://example.com")
    .retrieve()
    .bodyToMono(String.class);
response.subscribe(result -> System.out.println(result));

Handling Errors

Açıklaması şöyle

RestTemplate’s error handling occurs through the ErrorHandler interface, which requires a separate block of code. WebClient streamlines this with more fluent handling.

Örnek

Şöyle yaparız

WebClient webClient = WebClient.create();
webClient.get()
    .uri("http://example.com/some-error-endpoint")
    .retrieve()
    .onStatus(HttpStatus::isError, response -> {
        // Handle error status codes
        return Mono.error(new CustomException("Custom error occurred."));
    })
    .bodyToMono(String.class);

Açıklaması şöyle

The onStatus() method allows for handling specific HTTP statuses directly within the chain of operations, providing a more readable and maintainable approach.

POST

Örnek

Şöyle yaparız

RestTemplate restTemplate = new RestTemplate();
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON);
HttpEntity<String> request = new HttpEntity<>("{\"key\":\"value\"}", headers);
ResponseEntity<String> response = restTemplate
  .postForEntity("http://example.com",  request, String.class);

WebClient webClient = WebClient.create();
Mono<String> response = webClient.post()
    .uri("http://example.com")
    .contentType(MediaType.APPLICATION_JSON)
    .bodyValue("{\"key\":\"value\"}")
    .retrieve()
    .bodyToMono(String.class);

Asynchronous Processing