Feign调用中的两种Header传参方式

在请求拦截器中统一配置
适用于当一个调用链涉及到多个微服务，一些参数需要在整个调用链中传递。比如为了安全每个服务都需要对请求头中token的校验。

import feign.RequestInterceptor;
import feign.RequestTemplate;
import lombok.extern.slf4j.Slf4j;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.http.HttpServletRequest;
import java.util.Enumeration;

/**
 * 请求拦截器,将原始请求header中数据原样通过feign传输
 *
 * @Author xiyang
 * @Date 2022/10/21
 */
@Slf4j
@Configuration
public class FeignConfig implements RequestInterceptor {

    @Override
    public void apply(RequestTemplate requestTemplate) {
        RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
        if (requestAttributes == null) {
            // 从MQ收到消息时需要RPC
            log.info("requestAttributes is null");
            return;
        }

        ServletRequestAttributes attributes = (ServletRequestAttributes) requestAttributes;
        HttpServletRequest request = attributes.getRequest();
        Enumeration<String> headerNames = request.getHeaderNames();
        if (headerNames != null) {
            while (headerNames.hasMoreElements()) {
                String name = headerNames.nextElement();
                String values = request.getHeader(name);

                // 跳过 content-length, 防止RPC时参数长度与请求时不一致
                if ("content-length".equalsIgnoreCase(name)) {
                    continue;
                }

                requestTemplate.header(name, values);
            }
        }
    }
}

然后在feignClient中配置自定义的配置类，覆盖默认的配置

@FeignClient(value = "service-name", configuration = FeignConfig.class)
public interface FeignTest {
}

通过@RequestHeader注解
有时候我们需要传一些自定义的header参数，而不需要传全部header参数，只需要在调用的接口上添加@RequestHeader注解，Feign调用时，会自动封装成header参数

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestHeader;

@FeignClient(value = "service-name")
public interface FeignTest {
    
    /**
     * 通过 @RequestHeader 将参数封装到HTTP header中
     *
     * @param token
     * @param msgId
     */
    @GetMapping(value = "/test")
    void test(@RequestHeader("x-token") String token, @RequestHeader("x-msgId") String msgId);
}

最后编辑于：2023.04.17 16:29:49