關於Feign呼叫服務Headers傳參問題

2022-03-04 16:00:31

Feign呼叫服務Headers傳參

在使用springcloud中經常會出現個服務呼叫，一般情況下會在Headers加上token的驗證，那麼在feign呼叫時候我們怎麼去傳這個token過去呢，有人會用@Headers這個註解來實現。但是這樣方法太多笨重。

我們可以使用RequestInterceptor來實現

附上程式碼

    import feign.RequestInterceptor;
    import feign.RequestTemplate;
    import org.springframework.stereotype.Component;
    import org.springframework.web.context.request.RequestContextHolder;
    import org.springframework.web.context.request.ServletRequestAttributes;
    import javax.servlet.http.HttpServletRequest;
    import java.util.Enumeration;
    @Component
    public class SecuringRequestInterceptor implements RequestInterceptor {
        @Override
        public void apply(RequestTemplate requestTemplate) {
            ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder
                    .getRequestAttributes();
            HttpServletRequest request = attributes.getRequest();
            Enumeration<String> headerNames = request.getHeaderNames();
            if (headerNames != null) {
                while (headerNames.hasMoreElements()) {
                    String name = headerNames.nextElement();
                    String values = request.getHeader("Ttoken");
                    requestTemplate.header("Ttoken", values);
                }
            }
        }
    }

Feign設定Header頭部,@Headers無效

在使用FeignClient呼叫外部介面的時候，需要在請求頭部新增header的引數，用於請求的認證。在查詢Feign檔案中提供了@Headers註解，該註解可以完成頭部的新增。但是卻沒有生效

@FeignClient(name="name",url = "127.0.0.1:8090/test",path = "/")
public interface IUserService {
 
    @RequestMapping(value = "getUserPage",method = RequestMethod.POST)
    @Headers(value={"ContentType=application/x-www-form-urlencoded","Inner_token=PXH0dP5I8qQ8UbFPpzm67cQkm7j8tWT2Kwn6J6SXYkfp2kMo/lSqHQ=="})
    public Map<String,Object> getUserPage(User user);
}

在伺服器端獲取不到Inner_token的頭部引數。得到的結果是null

於是開啟feign的紀錄檔

第一步：定義feign的紀錄檔組態檔類

@Configuration
public class FeignConfig {
 
    @Bean
    Logger.Level feignLevel(){
        return Logger.Level.FULL;
    }
}

第二步：在呼叫的FeignClien使用者端註解上指定該紀錄檔級別組態檔

@FeignClient(name="name",url = "127.0.0.1:8090/test",path = "/",configuration = FeignConfig.class)
public interface IUserService {
 
    @RequestMapping(value = "getUserPage",method = RequestMethod.POST)
    @Headers(value={"ContentType=application/x-www-form-urlencoded","Inner_token=PXH0dP5I8qQ8UbFPpzm67cQkm7j8tWT2Kwn6J6SXYkfp2kMo/lSqHQ=="})
    public Map<String,Object> getUserPage(User user);
}

第三步：設定yml檔案，指定該feignclient的設定路徑和紀錄檔級別

logging:
  level:
    demo.IUserService: debug

重啟，並行起請求

2019-09-27 10:46:01.662 DEBUG 15200 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] ---> POST http://127.0.0.1:8090/test/getUserPage HTTP/1.1
2019-09-27 10:46:01.663 DEBUG 15200 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] Content-Type: application/json;charset=UTF-8
2019-09-27 10:46:01.663 DEBUG 15200 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] Content-Length: 53
2019-09-27 10:46:01.663 DEBUG 15200 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage]
2019-09-27 10:46:01.663 DEBUG 15200 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] {"id":0,"tableName":"feignTable","page":10,"size":10}
2019-09-27 10:46:01.663 DEBUG 15200 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] ---> END HTTP (53-byte body)
2019-09-27 10:46:01.684 DEBUG 15200 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] <--- HTTP/1.1 200 (21ms)
2019-09-27 10:46:01.684 DEBUG 15200 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] content-type: application/json;charset=UTF-8
2019-09-27 10:46:01.685 DEBUG 15200 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] date: Fri, 27 Sep 2019 02:46:01 GMT
2019-09-27 10:46:01.685 DEBUG 15200 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] transfer-encoding: chunked
2019-09-27 10:46:01.685 DEBUG 15200 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] x-application-context: HelloServer:8090
2019-09-27 10:46:01.685 DEBUG 15200 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage]
2019-09-27 10:46:01.689 DEBUG 15200 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] {"success":true,"rows":[{"id":10111,"tableName":"hbaseTable","page":1,"size":20},{"id":10112,"tableName":"hbaseTable","page":1,"size":20},{"id":10113,"tableName":"hbaseTable","page":1,"size":20},{"id":10114,"tableName":"hbaseTable","page":1,"size":20},{"id":10115,"tableName":"hbaseTable","page":1,"size":20},{"id":10116,"tableName":"hbaseTable","page":1,"size":20},{"id":10117,"tableName":"hbaseTable","page":1,"size":20},{"id":10118,"tableName":"hbaseTable","page":1,"size":20},{"id":10119,"tableName":"hbaseTable","page":1,"size":20},{"id":10120,"tableName":"hbaseTable","page":1,"size":20}]}
2019-09-27 10:46:01.689 DEBUG 15200 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] <--- END HTTP (595-byte body)

在紀錄檔中發現，header中沒有被加上我之前設定的引數。說明該註解沒有生效

於是debug偵錯

通過debug我發現feign會先將請求引數構建成Request物件，request資訊如下：

從圖中可看到，該Request範例的headers屬性為空，而Request又是根據RequestTemplate模板物件生成的，RequestTemplate範例資訊如下：

到這裡可以看出，問題是出在RequestTemplate的構建構成中，於是我就去跟蹤RequestTemplate構建的程式碼，發現RequestTemplate是根據MethodMetadata構建而成，而MethodMetadata就是對方法設定的抽象。

RequestTemplate template = resolve(argv, mutable, varBuilder);
      if (metadata.queryMapIndex() != null) {
        // add query map parameters after initial resolve so that they take
        // precedence over any predefined values
        template = addQueryMapQueryParameters(argv, template);
      }
 
      if (metadata.headerMapIndex() != null) {
        template = addHeaderMapHeaders(argv, template);
      }

從上述程式碼可以看到，header的設定是由metadata的headerMapIndex 屬性決定的，那麼，設定headerMapIndex的位置，必然就和Header的解析相關，於是通過檢視方法參照，我找到了下面的程式碼：

private void parseHeaders(MethodMetadata md, Method method,
            RequestMapping annotation) {
        // TODO: only supports one header value per key
        if (annotation.headers() != null && annotation.headers().length > 0) {
            for (String header : annotation.headers()) {
                int index = header.indexOf('=');
                if (!header.contains("!=") && index >= 0) {
                    md.template().header(resolve(header.substring(0, index)),
                        resolve(header.substring(index + 1).trim()));
                }
            }
        }
    }

從程式碼中我們可以清晰的看到，解析過程中是從@RequestMapping或其派生註解的header屬性中解析Header的，並且Header的key和value需要用“=”進行分割。

於是我修改成下面的形式，問題就解決了：

@FeignClient(name="name",url = "127.0.0.1:8090/test",path = "/",configuration = FeignConfig.class)
public interface IUserService {
 
    @RequestMapping(value = "getUserPage",method = RequestMethod.POST,headers = {"ContentType=application/x-www-form-urlencoded","Inner_token=PXH0dP5I8qQ8UbFPpzm67cQkm7j8tWT2Kwn6J6SXYkfp2kMo/lSqHQ=="})
    @Headers(value={"ContentType=application/x-www-form-urlencoded","Inner_token=PXH0dP5I8qQ8UbFPpzm67cQkm7j8tWT2Kwn6J6SXYkfp2kMo/lSqHQ=="})
    public Map<String,Object> getUserPage(User user);
}

檢視請求紀錄檔

2019-09-27 11:10:29.975 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] ---> POST http://127.0.0.1:8090/test/getUserPage HTTP/1.1
2019-09-27 11:10:29.976 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] ContentType: application/x-www-form-urlencoded
2019-09-27 11:10:29.976 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] Inner_token: PXH0dP5I8qQ8UbFPpzm67cQkm7j8tWT2Kwn6J6SXYkfp2kMo/lSqHQ==
2019-09-27 11:10:29.976 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] Content-Type: application/json;charset=UTF-8
2019-09-27 11:10:29.976 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] Content-Length: 53
2019-09-27 11:10:29.976 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage]
2019-09-27 11:10:29.976 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] {"id":0,"tableName":"feignTable","page":10,"size":10}
2019-09-27 11:10:29.976 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] ---> END HTTP (53-byte body)
2019-09-27 11:10:29.992 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] <--- HTTP/1.1 200 (16ms)
2019-09-27 11:10:29.993 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] content-type: application/json;charset=UTF-8
2019-09-27 11:10:29.993 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] date: Fri, 27 Sep 2019 03:10:29 GMT
2019-09-27 11:10:29.993 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] transfer-encoding: chunked
2019-09-27 11:10:29.993 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] x-application-context: HelloServer:8090
2019-09-27 11:10:29.993 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage]
2019-09-27 11:10:29.995 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] {"success":true,"rows":[{"id":10141,"tableName":"hbaseTable","page":1,"size":20},{"id":10142,"tableName":"hbaseTable","page":1,"size":20},{"id":10143,"tableName":"hbaseTable","page":1,"size":20},{"id":10144,"tableName":"hbaseTable","page":1,"size":20},{"id":10145,"tableName":"hbaseTable","page":1,"size":20},{"id":10146,"tableName":"hbaseTable","page":1,"size":20},{"id":10147,"tableName":"hbaseTable","page":1,"size":20},{"id":10148,"tableName":"hbaseTable","page":1,"size":20},{"id":10149,"tableName":"hbaseTable","page":1,"size":20},{"id":10150,"tableName":"hbaseTable","page":1,"size":20}]}
2019-09-27 11:10:29.995 DEBUG 8604 --- [ hystrix-name-1] demo.IUserService : [IUserService#getUserPage] <--- END HTTP (595-byte body)

請求中header已經被成功新增

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