在請求攔截器中統(tǒng)一配置
適用于當(dāng)一個(gè)調(diào)用鏈涉及到多個(gè)微服務(wù)湾戳，一些參數(shù)需要在整個(gè)調(diào)用鏈中傳遞。比如為了安全每個(gè)服務(wù)都需要對請求頭中token的校驗(yàn)几蜻。

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;

/**
 * 請求攔截器,將原始請求header中數(shù)據(jù)原樣通過feign傳輸
 *
 * @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) {
            // 從MQ收到消息時(shí)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);

                // 跳過 content-length, 防止RPC時(shí)參數(shù)長度與請求時(shí)不一致
                if ("content-length".equalsIgnoreCase(name)) {
                    continue;
                }

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

然后在feignClient中配置自定義的配置類姻锁，覆蓋默認(rèn)的配置

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

通過@RequestHeader注解
有時(shí)候我們需要傳一些自定義的header參數(shù)，而不需要傳全部header參數(shù)渴析，只需要在調(diào)用的接口上添加@RequestHeader注解晚伙，F(xiàn)eign調(diào)用時(shí)吮龄，會(huì)自動(dòng)封裝成header參數(shù)

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 {
    
    /**
     * 通過 @RequestHeader 將參數(shù)封裝到HTTP header中
     *
     * @param token
     * @param msgId
     */
    @GetMapping(value = "/test")
    void test(@RequestHeader("x-token") String token, @RequestHeader("x-msgId") String msgId);
}