丟失請求頭

feign遠程調(diào)用如果不對之進行增強价匠，則會丟失請求頭。
Feign遠程調(diào)用前麦牺，會通過遍歷容器中的Feign包下的攔截器RequestInterceptor判斷是否為當前的RequestTemplate進行增強。
遠程調(diào)用核心代碼

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遍歷private final List<RequestInterceptor> requestInterceptors;

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解決方案

裝配一個RequestInterceptor 的bean實例乔煞，對RequestTemplate進行增強吁朦。

@Configuration
public class GuliFeignConfig {
    @Bean
    public RequestInterceptor requestInterceptor() {
        return new RequestInterceptor() {
            @Override
            public void apply(RequestTemplate template) {
                //1. 使用RequestContextHolder拿到老請求的請求數(shù)據(jù)
                ServletRequestAttributes requestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
                if (requestAttributes != null) {
                    HttpServletRequest request = requestAttributes.getRequest();
                    if (request != null) {
                        //2. 將老請求得到cookie信息放到feign請求上
                        String cookie = request.getHeader("Cookie");
                        template.header("Cookie", cookie);
                    }
                }
            }
        };
    }
}

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異步線程丟失上下文

異步調(diào)用的時候，第十一行會報空指針

@Configuration
public class GuliFeignConfig {
    @Bean
    public RequestInterceptor requestInterceptor() {
        return new RequestInterceptor() {
            @Override
            public void apply(RequestTemplate template) {
                //1. 使用RequestContextHolder拿到老請求的請求數(shù)據(jù)
                ServletRequestAttributes requestAttributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
                if (requestAttributes != null) {
                    HttpServletRequest request = requestAttributes.getRequest();
                    if (request != null) {
                        //2. 將老請求得到cookie信息放到feign請求上
                        String cookie = request.getHeader("Cookie");
                        template.header("Cookie", cookie);
                    }
                }
            }
        };
    }
}

因為異步調(diào)用會創(chuàng)建新線程渡贾，無法獲取主線程的數(shù)據(jù)逗宜。
解決辦法
利用RequestContextHolder通過ThreadLocal共享數(shù)據(jù)的特性，先在主線程中獲取主線程的RequestAttributes，后在子線程中RequestContextHolder.setRequestAttributes(requestAttributes);

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    @Override
    public ResponseResult<OrderConfirm> confirmOrder() {
      
        RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
      
        CompletableFuture<Object> objectFuture = CompletableFuture.supplyAsync(() -> {
            RequestContextHolder.setRequestAttributes(requestAttributes);
            //xxxx
            return Object;
        }, executor);
      }
  
}