Feign的拦截器RequestInterceptor

Feign的拦截器RequestInterceptor

SpringCloud的微服务使用Feign进行服务间调用的时候可以使用RequestInterceptor统一拦截请求来完成设置header等相关请求，但RequestInterceptor和ClientHttpRequestInterceptor有点不同，它拿不到原本的请求，所以要通过其他方法来获取原本的请求

首先创建自定义的RequestInterceptor

这里通过RequestContextHolder获取到当前的request

@Slf4j
@Component
public class MyFeignInterceptor implements RequestInterceptor {
    @Override
    public void apply(RequestTemplate template) {

        ServletRequestAttributes servletRequestAttributes = (ServletRequestAttributes)RequestContextHolder.getRequestAttributes();

        log.info("===request: {}", template.url());
        template.header("aaaa", "bbbb");
    }
}

然后定义一个feign的接口类

@FeignClient(name = "SPRING-CLOUD-CLIENT-DEMO")
public interface ClientFeign {

    @GetMapping("/demo/get")
    String weight(@RequestParam String param);
}

再创建一个controller

@Slf4j
@RestController
@RequestMapping("/interceptor")
public class InterceptorController {

    @Autowired
    private ClientFeign clientFeign;


    @GetMapping("/feign")
    public String feign(@RequestParam String param) {

        return clientFeign.weight(param);
    }

}

运行程序测试一下接口

查看程序打印

可以看到进入了我们自定义的RequestInterceptor

INFO 25936 --- [ctor-http-nio-3] c.m.d.g.interceptor.MyFeignInterceptor   : ===request: /demo/weight?param=a

再查看feign调用的程序日志，可以看到设置的header信息

INFO 1 --- [nio-8801-exec-6] c.m.d.client.controller.DemoController   : aaaa: a
  INFO 1 --- [nio-8801-exec-6] c.m.d.client.controller.DemoController   : websession: ECF4D97D02EEAFDDA3C15A7F1F050F61
  INFO 1 --- [nio-8801-exec-6] c.m.d.client.controller.DemoController   : header: aaaa, bbbb
  INFO 1 --- [nio-8801-exec-6] c.m.d.client.controller.DemoController   : header: accept, */*
  INFO 1 --- [nio-8801-exec-6] c.m.d.client.controller.DemoController   : header: user-agent, Java/1.8.0_191
  INFO 1 --- [nio-8801-exec-6] c.m.d.client.controller.DemoController   : header: host, 39.108.15.147:8801
  INFO 1 --- [nio-8801-exec-6] c.m.d.client.controller.DemoController   : header: connection, keep-alive