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

@SpringBootApplication
@EnableFeignClients  // 啟用 Feign 客戶端
public class FeignApplication {

    public static void main(String[] args) {
        SpringApplication.run(FeignApplication.class, args);
    }
}

feign:
  client:
    config:
      default:
        connectTimeout: 5000     # 連接超時(shí)時(shí)間
        readTimeout: 5000        # 讀取超時(shí)時(shí)間
  httpclient:
    enabled: true                # 啟用 HttpClient 作為 Feign 的底層實(shí)現(xiàn)
logging:
  level:
    com.example: DEBUG           # 設(shè)置日志級(jí)別為 DEBUG

@FeignClient(name = "user-service", url = "http://localhost:8081")  // 定義 Feign 客戶端
public interface UserClient {

    @GetMapping("/users/{id}")
    User getUserById(@PathVariable("id") Long id);
}

public class User {
    private Long id;
    private String name;
    private String email;

    // getters and setters
}

@RestController
@RequestMapping("/orders")
public class OrderController {

    @Autowired
    private UserClient userClient;

    @GetMapping("/{id}/user")
    public User getUserByOrderId(@PathVariable("id") Long orderId) {
        // 通過(guò) Feign 調(diào)用用戶服務(wù)
        User user = userClient.getUserById(orderId);
        return user;
    }
}

@FeignClient(name = "user-service")  // 通過(guò) Eureka 服務(wù)發(fā)現(xiàn)獲取服務(wù)地址
public interface UserClient {
    @GetMapping("/users/{id}")
    User getUserById(@PathVariable("id") Long id);
}

ribbon:
  eureka:
    enabled: true   # 啟用與 Eureka 的集成
  NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RoundRobinRule  # 負(fù)載均衡策略，輪詢

@Configuration
public class FeignConfig {

    @Bean
    public Request.Options options() {
        return new Request.Options(5000, 10000);  // 設(shè)置連接超時(shí)和讀取超時(shí)
    }

    @Bean
    public Logger.Level feignLoggerLevel() {
        return Logger.Level.FULL;  // 設(shè)置日志級(jí)別為 FULL
    }
}

@FeignClient(name = "user-service", configuration = FeignConfig.class)
public interface UserClient {
    @GetMapping("/users/{id}")
    User getUserById(@PathVariable("id") Long id);
}

feign:
  hystrix:
    enabled: true  # 啟用 Feign 的 Hystrix 降級(jí)功能

@FeignClient(name = "user-service", fallback = UserClientFallback.class)
public interface UserClient {
    @GetMapping("/users/{id}")
    User getUserById(@PathVariable("id") Long id);
}

// 定義降級(jí)類(lèi)
@Component
public class UserClientFallback implements UserClient {

    @Override
    public User getUserById(Long id) {
        // 返回默認(rèn)的用戶信息
        User user = new User();
        user.setId(id);
        user.setName("Default User");
        user.setEmail("default@example.com");
        return user;
    }
}

logging:
  level:
    com.example: DEBUG  # 開(kāi)啟 DEBUG 級(jí)別日志
    feign:
      Logger: FULL       # 記錄 Feign 的詳細(xì)日志

@SpringBootApplication
@EnableFeignClients
public class FeignApplication {

    public static void main(String[] args) {
        SpringApplication.run(FeignApplication.class, args);
    }
}

@FeignClient(name = "user-service", fallback = UserClientFallback.class)
public interface UserClient {

    @GetMapping("/users/{id}")
    User getUserById(@PathVariable("id") Long id);
}

@Component
public class UserClientFallback implements UserClient {

    @Override
    public User getUserById(Long id) {
        User user = new User();
        user.setId(id);
        user.setName("Default User");
        user.setEmail("default@example.com");
        return user;
    }
}

@RestController
@RequestMapping("/orders")
public class OrderController {

    @Autowired
    private UserClient userClient;

    @GetMapping("/{id}/user")
    public User getUserByOrderId(@PathVariable("id") Long orderId) {
        return userClient.getUserById(orderId);
    }
}