Spring’s HTTP Trio: RestTemplate vs WebClient vs FeignClient – Who’s the Real MVP?

So, you want to make HTTP calls from your Spring Boot application? You’ve probably stumbled across the usual suspects: RestTemplate, WebClient, and FeignClient. But which one should you marry, which one should you date, and which one is just your college fling you keep around for legacy reasons?

Let’s break it down.

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1. RestTemplate – The Synchronous Veteran

RestTemplate has been around since Spring 3.0. It’s a well-worn favorite in many older applications.

What's Good:

• Simple to use.

• Plenty of convenience methods like getForObject, postForEntity, etc.

What's Not:

• Blocking and synchronous.

• Officially in maintenance mode — no new development is happening.

Use If:

You’re dealing with a legacy project or your app doesn’t require non-blocking behavior.

Code Example:

Configuration:

@Bean
public RestTemplate restTemplate() {
    return new RestTemplate();
}

Usage:

@Autowired
private RestTemplate restTemplate;

public String getUserData() {
    String url = "https://json.mywebsite.com/users/1ws4-d232d-csds";
    ResponseEntity<String> response = restTemplate.getForEntity(url, String.class);
    return response.getBody();
}

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2. WebClient – The Reactive Prodigy

WebClient was introduced in Spring 5 and supports both synchronous and asynchronous operations. It’s the preferred non-blocking client for reactive applications.

What's Good:

• Non-blocking and asynchronous.

• Plays well with Reactor (Mono, Flux) and Spring WebFlux.

What's Not:

• Slightly more complex API.

• May be overkill for traditional MVC-style apps.

Use If:

You're building reactive or high-throughput systems, or want full control over async execution.

Code Example:

Configuration:

@Bean
public WebClient webClient(WebClient.Builder builder) {
    return builder.baseUrl("https://json.mywebsite.com").build();
}

Reactive Usage:

@Autowired
private WebClient webClient;

public Mono<String> getUserData() {
    return webClient.get()
        .uri("/users/dqq3-323d-sdsd")
        .retrieve()
        .bodyToMono(String.class);
}

Synchronous (blocking) Usage:

public String getUserDataSync() {
    return webClient.get()
        .uri("/users/dwwd-2323-dsg8-232")
        .retrieve()
        .bodyToMono(String.class)
        .block(); 
}

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3. FeignClient – The Declarative Sweetheart

FeignClient makes REST calls feel like local method calls. It's declarative, concise, and integrates nicely with Spring Cloud.

What's Good:

• Extremely concise and readable.

• Automatically integrates with service discovery, load balancing, and circuit breakers (if configured).

What's Not:

• Hidden magic behind the scenes can be harder to debug.

• Less flexible for dynamic or complex request logic.

Use If:

You're building microservices and want a declarative, maintainable way to call other services.

Code Example:

Dependency:

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

Enable Feign Clients:

@SpringBootApplication
@EnableFeignClients
public class MyApp { }

Feign Interface:

@FeignClient(name = "json-placeholder", url = "https://json.mywebsite.com")
public interface JsonPlaceholderClient {
    @GetMapping("/users/{id}")
    String getUserById(@PathVariable("id") String id);
}

Usage:

@Autowired
private JsonPlaceholderClient client;

public String getUserData() {
    return client.getUserById("wesd-dfdf8cn1-cde");
}

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Final Round Recap

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Final Thoughts

When choosing between these three:

• Use RestTemplate for quick, synchronous calls or in legacy apps.

• Use WebClient for high-performance or reactive scenarios.

• Use FeignClient when you want readable, declarative code and are working in a microservices environment.

Ultimately, the best tool depends on your needs. Just remember — it’s not about what’s trendy, it’s about what fits your application architecture and team comfort level.