Spring Boot 调用外部接口的几种方式

import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.web.client.RestTemplate;

// REST GET请求
RestTemplate restTemplate = new RestTemplate();
String resultGet = restTemplate.getForObject("http://example.com/endpoint", String.class);

// REST POST请求
HttpHeaders headers = new HttpHeaders();
headers.set("Custom-Header", "Custom header value");
HttpEntity<String> entity = new HttpEntity<>(headers);
String resultPost = restTemplate.postForObject("http://example.com/endpoint", entity, String.class);

import org.springframework.web.reactive.function.client.WebClient;

// 创建WebClient
WebClient webClient = WebClient.create("http://example.com");

// REST GET请求
String resultGet = webClient.get()
        .uri("/endpoint")
        .retrieve()
        .bodyToMono(String.class)
        .block();

// REST POST请求
String resultPost = webClient.post()
        .uri("/endpoint")
        .header("Custom-Header", "Custom header value")
        .retrieve()
        .bodyToMono(String.class)
        .block();

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;

// 定义Feign接口
@FeignClient(name = "example-service", url = "http://example.com")
public interface ExampleClient {
    @GetMapping("/endpoint")
    String exampleRequest();
}

// 调用Feign接口
@Autowired
private ExampleClient exampleClient;

public void doSomething() {
    String result = exampleClient.exampleRequest();
}