<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-webflux</artifactId>
</dependency>

// 使用 @HttpExchange 注解在接口上，定義所有方法的公共路徑
@HttpExchange(url = "/api/v1/users", accept = "application/json", contentType = "application/json")
public interface UserServiceClient {
    /**
     * 獲取所有用戶 - GET /api/v1/users
     */
    @GetExchange // 等價于 @HttpExchange(method = "GET")
    List<User> getAllUsers();
    /**
     * 根據(jù)ID獲取用戶 - GET /api/v1/users/{id}
     * 使用 @PathVariable 注解路徑參數(shù)
     */
    @GetExchange("/{id}")
    User getUserById(@PathVariable("id") Long id);
    /**
     * 創(chuàng)建新用戶 - POST /api/v1/users
     * 使用 @RequestBody 注解請求體
     */
    @PostExchange
    User createUser(@RequestBody User user);
    /**
     * 更新用戶信息 - PUT /api/v1/users/{id}
     */
    @PutExchange("/{id}")
    User updateUser(@PathVariable("id") Long id, @RequestBody User user);
    /**
     * 刪除用戶 - DELETE /api/v1/users/{id}
     * 返回 void 或特定的響應對象
     */
    @DeleteExchange("/{id}")
    void deleteUser(@PathVariable("id") Long id);
    /**
     * 搜索用戶 - GET /api/v1/users/search?name={name}
     * 使用 @RequestParam 注解查詢參數(shù)
     */
    @GetExchange("/search")
    List<User> searchUsers(@RequestParam String name);
}
// 用戶實體類
@Data // 使用 Lombok 簡化 getter/setter
@AllArgsConstructor
@NoArgsConstructor
class User {
    private Long id;
    private String name;
    private String email;
}

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.reactive.function.client.WebClient;
import org.springframework.web.reactive.function.client.support.WebClientAdapter;
import org.springframework.web.service.invoker.HttpServiceProxyFactory;
@Configuration
@EnableWebClients // 啟用聲明式 HTTP 客戶端功能
public class WebConfig {
    @Bean
    public UserServiceClient userServiceClient(WebClient.Builder builder) {
        // 1. 創(chuàng)建 WebClient 實例，指定基礎 URL
        WebClient webClient = builder
                .baseUrl("http://jsonplaceholder.typicode.com") // 一個免費的測試 API
                .build();
        // 2. 創(chuàng)建 HttpServiceProxyFactory
        HttpServiceProxyFactory factory = HttpServiceProxyFactory
                .builder(WebClientAdapter.forClient(webClient))
                .build();
        // 3. 創(chuàng)建客戶端代理實例
        return factory.createClient(UserServiceClient.class);
    }
}

import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
@RequiredArgsConstructor
public class MyBusinessService {
    private final UserServiceClient userServiceClient;
    public void processUserData() {
        // 調用遠程 API 就像調用本地方法一樣
        List<User> allUsers = userServiceClient.getAllUsers();
        System.out.println("All users: " + allUsers);
        User userById = userServiceClient.getUserById(1L);
        System.out.println("User with ID 1: " + userById);
        // ... 其他業(yè)務邏輯
    }
}

WebClient webClient = builder
    .baseUrl("http://localhost:8080")
    .filter((request, next) -> {
        return next.exchange(request)
            .onStatus(HttpStatusCode::isError, response -> {
                // 處理 4xx/5xx 錯誤
                return Mono.error(new RuntimeException("API call failed: " + response.statusCode()));
            });
    })
    .build();

.filter((request, next) -> {
    ClientRequest filteredRequest = ClientRequest.from(request)
            .header("Authorization", "Bearer " + myAuthToken)
            .build();
    return next.exchange(filteredRequest);
})