spring cloud之feign

1.引入依赖

 <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>
        <!--这个依赖 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
         <dependency>
             <groupId>org.springframework.retry</groupId>
             <artifactId>spring-retry</artifactId>
         </dependency>
         <dependency>
             <groupId>org.springframework.cloud</groupId>
             <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
         </dependency>

2.配置

server:
  port: 6063

spring:
  application:
    name: consumer-feign
  cloud:
    loadbalancer:
      retry:
        enabled: true # 开启Spring Cloud的重试功能
  main:
    allow-bean-definition-overriding: true
logging:
  level:
    com.d4c: debug

eureka:
  instance:
    prefer-ip-address: true
  client:
    register-with-eureka: true
    fetch-registry: true
    service-url:
      defaultZone: http://peer1:6001/eureka/,http://peer2:6002/eureka/

feign:
  hystrix:
    enabled: true # 开启Feign的熔断功能
  compression:
    request:
      enabled: true # 开启请求压缩
      mime-types: text/html,application/xml,application/json # 设置压缩的数据类型
      min-request-size: 2048 # 设置触发压缩的大小下限
    response:
      enabled: true # 开启响应压缩

ribbon:
  ConnectTimeout: 250 # Ribbon的连接超时时间
  ReadTimeout: 1000 # Ribbon的数据读取超时时间
  OkToRetryOnAllOperations: true # 是否对所有操作都进行重试
  MaxAutoRetriesNextServer: 1 # 切换实例的重试次数
  MaxAutoRetries: 1 # 对当前实例的重试次数

hystrix:
  command:
    default:
      execution:
        isolation:
          thread:
            timeoutInMilliseconds: 6000 # 设置hystrix的超时时间为6000ms

3.相关类

启动类

@SpringBootApplication
@EnableDiscoveryClient
@EnableHystrix//或者@EnableCircuitBreaker
@EnableFeignClients
public class ConsumerFeignApplication {
    public static void main(String[] args) {
        SpringApplication.run(ConsumerFeignApplication.class, args);
    }
}

FeignClient接口

@FeignClient(value = "account-demo",fallback = AccountClientFallback.class)
public interface AccountClient {

    @GetMapping("account/get/server/{id}")
    String queryAccountById(@PathVariable Long id);

    @GetMapping("account/get/{id}")
    String queryAccountByIdTwo(@PathVariable Long id);

}

FeignClient接口实现类

@Component
public class AccountClientFallback implements AccountClient {
    @Override
    public String queryAccountById(Long id) {
        return "I am fallback!";
    }

    @Override
    public String queryAccountByIdTwo(Long id) {
        return "I am fallback two!";
    }
}

service类

@Service
public class AccountConsumerService {


    @Autowired
    private AccountClient accountClient;


    public String queryAccountById(Long id) {
        String s = accountClient.queryAccountById(id);
        return s;
    }

    public String queryAccountByIdTwo(Long id) {
        String s = accountClient.queryAccountByIdTwo(id);
        return s;
    }
}

controller类

@RestController
@RequestMapping("account")
public class AccountConsumerController {

    @Resource
    private AccountConsumerService accountConsumerService;

    @RequestMapping("/{id}")
    public String queryAccountById(@PathVariable Long id){
        return accountConsumerService.queryAccountById(id);
    }

    @RequestMapping("/two/{id}")
    public String queryAccountByIdTwo(@PathVariable Long id){
        return accountConsumerService.queryAccountByIdTwo(id);
    }

}

feign自定的日志类

@Configuration
public class LogLevelConfig {
    @Bean
    Logger.Level feignLoggerLevel(){
        return Logger.Level.FULL;
    }
}

这里指定的Level级别是FULL，Feign支持4种级别：

NONE：不记录任何日志信息，这是默认值。
BASIC：仅记录请求的方法，URL以及响应状态码和执行时间
HEADERS：在BASIC的基础上，额外记录了请求和响应的头信息
FULL：记录所有请求和响应的明细，包括头信息、请求体、元数据。