引入启动
在配置类中加入@EnableFeignClients注解，该注解引入相关类FeignClientsRegistrar，通过此类进行客户端@FeignClient注册；@FeignClient注解放在接口类中。
配置
配置 | 说明 |
|---|---|
feign.circuitbreaker.enabled=true | 启用熔断器 |
feign.compression.request或者response.enabled | 请求压缩 |
feign.client.config.default.logger-level = full | 配置日志，其中default可以修改为具体的client name |
日志配置
feign的日志级别有:
NONE, 默认没有
BASIC, 记录方法、路径、响应状态、执行时间
HEADERS, 比BASIC多HEADER信息
FULL, header信息, 请求body, requests 和 responses元信息
可以在配置文件中配置，也可以通过代码配置
代码语言：java复制@Configuration
public class FooConfiguration {
@Bean
Logger.Level feignLoggerLevel() {
return Logger.Level.FULL;
}
}熔断器
1、配置@FeignClient中的fallback参数，fallback需要注册为bean
@FeignClient(name="provider",fallback=UserServiceCallback.class)
public interface UserService {
@RequestMapping(method = RequestMethod.GET, value = "/appone/home/")
public String addUser(@RequestParam String userid,@RequestParam String pwd,@RequestParam String say);
@RequestMapping(method = RequestMethod.GET, value = "/appone/home/")
public String delUser(@RequestParam String userid,@RequestParam String say);
@RequestMapping(method = RequestMethod.GET, value = "/appone/home/")
public String getUer(@RequestParam String userid,@RequestParam String say);
@RequestMapping(method = RequestMethod.GET, value = "/appone/home/allLogs/")
public Object allLogs(@RequestParam PageInfo pg,@RequestParam String title);
@RequestMapping(method = RequestMethod.POST, value = "/appone/home/delLog")
public ResponseMessage<Object> delLog(String id);
}
@Component
public class UserServiceCallback implements UserService {
Logger logger = LoggerFactory.getLogger(getClass());
@Override
public String addUser(String userid, String pwd, String say) {
return null;
}
@Override
public String delUser(String userid, String say) {
return null;
}
@Override
public String getUer(String userid, String say) {
return null;
}
@Override
public Object allLogs(PageInfo pg, String title) {
throw new NoFallbackAvailableException("Boom!", new RuntimeException());
}
@Override
public ResponseMessage<Object> delLog(String id) {
throw new NoFallbackAvailableException("Boom!", new RuntimeException());
}
}2、若要知道具体断路的原因，则需要fallbackFactory参数，也需要配置为bean
拦截器
拦截器用于拦截请求，可以增加认证参数
1、继承RequestInterceptor
public interface RequestInterceptor {
/**
* Called for every request. Add data using methods on the supplied {@link RequestTemplate}.
*/
void apply(RequestTemplate template);
}
public class MyInterceptor implements RequestInterceptor
{
@Override
public void apply(RequestTemplate template)
{
}
}2、注册
2.1 直接注册为bean
增加 @Component 或者 @Bean 注解
2.2 通过配置
feign.client.config.服务名.requestInterceptors0: com.xxx.xx
2.3 通过configuration
指定配置
原理
FeignClientsRegistrar继承了ImportBeanDefinitionRegistrar
class FeignClientsRegistrar implements ImportBeanDefinitionRegistrar, ResourceLoaderAware, EnvironmentAware {
@Override
public void registerBeanDefinitions(AnnotationMetadata metadata, BeanDefinitionRegistry registry) {
/// 注册默认的配置
registerDefaultConfiguration(metadata, registry);
/// 注册 @FeignClient 注解的类，并使用JDK动态代理（所以要求client必须是接口)
registerFeignClients(metadata, registry);
}
}
