Spring Cloud之Feign 转发请求头(header参数)

在做接口请求时，我们经常会在header头中增加一些鉴权信息，如token 或 jwt，那么在通过fegin从A server去调用B server的接口时，如果B server的接口需要header信息，我们需要将A sever获取的header转发到B上。

解决方式

我们需要实现Feign提供的一个接口RequestInterceptor

1@Configuration
2public class FeignConfiguration implements RequestInterceptor{
3    private final Logger logger = LoggerFactory.getLogger(getClass());
4
5            @Override
6            public void apply(RequestTemplate template) {
7                ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder
8                        .getRequestAttributes();
9                HttpServletRequest request = attributes.getRequest();
10                Enumeration<String> headerNames = request.getHeaderNames();
11                if (headerNames != null) {
12                    while (headerNames.hasMoreElements()) {
13                        String name = headerNames.nextElement();
14                        String values = request.getHeader(name);
15                        template.header(name, values);
16
17                    }
18                    logger.info("feign interceptor header:{}",template);
19                }
20               /* Enumeration<String> bodyNames = request.getParameterNames();
21                StringBuffer body =new StringBuffer();
22                if (bodyNames != null) {
23                    while (bodyNames.hasMoreElements()) {
24                        String name = bodyNames.nextElement();
25                        String values = request.getParameter(name);
26                        body.append(name).append("=").append(values).append("&");
27                    }
28                }
29                if(body.length()!=0) {
30                    body.deleteCharAt(body.length()-1);
31                    template.body(body.toString());
32                    //logger.info("feign interceptor body:{}",body.toString());
33                }*/
34            }
35        }

在@FeignClient注解里面的属性加上configuration = FeignConfiguration.class就可以了。如

1@FeignClient(name = "a-server",  configuration = FeignConfiguration.class)
2public interface AServer{
3}

bootstrap.yml增加

1hystrix:
2  command:
3    default:
4      execution:
5        timeout:
6          enabled: false
7        isolation:
8          strategy: SEMAPHORE