无法解析此服务器请求中的 EDN

Question

我认为我做对了，但我无法将我的 EDN 从 :body 输入流中取出。 Ring 和 Compojure 处理程序是这样的：

依赖：

 [ring.middleware.params :as params]
 [ring.middleware.edn :as edn]; https://github.com/tailrecursion/ring-edn

处理程序：

(defroutes ajax-example
  (PUT "/ajax-example" r
       (println r)
       {:status 200
        :headers {"Content-Type" "application/edn"}
        :body "yo"}))

我把它包装成这样：

  (def ajax-wrapped
   (-> ajax-example
      edn/wrap-edn-params
      params/wrap-params))

println'd 响应正确地显示它是 EDN，并且根据我发送的简单测试地图，内容长度是正确的，但地图本身无处可寻，它永远被困在输入流中:body... 怎么弄？

这是响应 println:

{:ssl-client-cert nil, :remote-addr 0:0:0:0:0:0:0:1, :params {}, :route-params {}, :headers {origin @987654321 @, 主机 localhost:6542, 用户代理 Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.135 Safari/537.36, content-type application/edn, cookie _ga= GA1.1.1354518981.1429622648； content-length 20, referer http://localhost:6542/, connection keep-alive, accept /, accept-language en-US,en;q=0.8,sq;q=0.6, accept-encoding gzip, deflate , sdch, 缓存控制 max-age=0}, :server-port 6542, :content-length 20, :form-params {}, :query-params {}, :content-type application/edn, :character- encoding nil, :uri /ajax-example, :server-name localhost, :query-string nil, :body #, :edn-params nil, :scheme :http, :request-method :put}

:body 上面没有正确粘贴，看起来像这样：

 [open corner bracket] HttpInput org.eclipse.jetty.server.HttpInput@5d969109 [end corner bracket]

使用cljs-ajax lib 从浏览器发送的客户端代码是：

(defn ajax-send
  []
  (let [push {:adder1 2 :add2 3}]
    (PUT "/ajax-example" 
         {:format :edn 
          :params push
          :handler ajax-result
          :error-handler error-handler})))

以下是其中一个答案建议的测试输出：

hf.examples> ((-> ajax-example  params/wrap-params edn/wrap-edn-params) (-> (mock/request :put "/ajax-example")
                                                             (mock/content-type "application/edn")
                                                             (mock/body "{:hello \"there\"}"))) 
{:status 200,
 :headers {"Content-Type" "application/edn"},
 :body
 "{:remote-addr \"localhost\", :params {:hello \"there\"}, :route-params {}, :headers {\"content-length\" \"16\", \"content-type\" \"application/edn\", \"host\" \"localhost\"}, :server-port 80, :content-length 16, :form-params {}, :query-params {}, :content-type \"application/edn\", :uri \"/ajax-example\", :server-name \"localhost\", :query-string nil, :edn-params {:hello \"there\"}, :scheme :http, :request-method :put}"}
hf.examples> 

我也试过这个：

(defroutes ajax-example
  (PUT "/ajax-example" r
       {:status 200
        :headers {"Content-Type" "application/edn"}
        :body (pr-str (dissoc r :body))}))

卷曲结果独立于前端：

curl -X PUT -H "Content-Type: application/edn" -d '{:name :barnabas}' http://localhost:6542/ajax-example
{:ssl-client-cert nil, :remote-addr "0:0:0:0:0:0:0:1", :params {}, :route-params {}, :headers {"host" "localhost:6542", "content-length" "17", "content-type" "application/edn", "user-agent" "curl/7.37.1", "accept" "*/*"}, :server-port 6542, :content-length 17, :content-type "application/edn", :character-encoding nil, :uri "/ajax-example", :server-name "localhost", :query-string nil, :edn-params nil, :scheme :http, :request-method

content-length（共 17 个）与通过 Curl 传递的映射中的字符数匹配。但是edn-params 是零！内容在哪里？

Answer 1

编辑：作为更新问题的答案，wrap-edn-params 函数通过完全读取 :body InputStream 来消耗请求的正文。 Compojure 路由将请求传递给每个参数处理程序，直到返回非 nil 值。在这种情况下，作为第一个处理程序传递给路由的任何处理程序都将消耗 :body 并且将没有 :body 值供第二个处理程序使用，从而导致 wrap-edn-params 读取的主体值为零。

传递给环处理程序的请求可能没有将其内容类型设置为 edn。 wrap-edn-params function 只会在请求内容类型设置为 edn 时解析 edn。

此外，解析后的edn参数只会被wrap-edn-params函数放在请求映射的:params和:edn-params键中，因此:body不应该用于访问解析后的edn。

(require '[ring.mock.request :as mock])
(require '[ring.middleware.edn :as edn]) 

((-> ajax-example  params/wrap-params edn/wrap-edn-params) (-> (mock/request :put "/ajax-example")
                                                             (mock/content-type "application/edn")
                                                             (mock/body "{:hello \"there\"}"))) 

{:remote-addr "localhost",
 :params {:hello "there"},
 :route-params {},
 :headers
 {"content-length" "16",
  "content-type" "application/edn",
  "host" "localhost"},
 :server-port 80,
 :content-length 16,
 :form-params {},
 :query-params {},
 :content-type "application/edn",
 :uri "/ajax-example",
 :server-name "localhost",
 :query-string nil,
 :body #<ByteArrayInputStream java.io.ByteArrayInputStream@171788d8>,
 :edn-params {:hello "there"},
 :scheme :http,
 :request-method :put}

Answer 2

我已经解决了这个问题，但我不知道为什么会出现问题。我有另一条独立的路线，也包裹了 EDN 中间件。这是可重现的示例：

(defroutes example-routes2
  (PUT "/test-edn" r
       (println r)
       {:status 200
        :headers {"Content-Type" "application/edn"}
        :body (pr-str (str "request is: " r))}))

(defroutes ajax-example
  (PUT "/ajax-example" r
       (println r)
       {:status 200
        :headers {"Content-Type" "application/edn"}
        :body (pr-str (str "request is: " r))}))

(def edn-routes 
  (-> example-routes2
      edn/wrap-edn-params))

(def ajax-wrapped
  (-> ajax-example
      edn/wrap-edn-params))

;;combining all routes on this page into a single handler
(def example-routes (routes example-routes1  ajax-wrapped edn-routes))

请注意，这两条路线本质上是相同的，并且包装相同。 未能将 EDN 解析为 edn-params 的是example-routes def! 中列出的第二个！

curl -X PUT -H "Content-Type: application/edn" -d '{:name :barnabasss}' http://localhost:6542/test-edn

返回：

"请求是：{:ssl-client-cert nil, :remote-addr \"0:0:0:0:0:0:0:1\", :params {}, :route-params { }, :headers {\"host\" \"localhost:6542\", \"content-length\" \"19\", \"content-type\" \"application/edn\", \"user-代理\" \"curl/7.37.1\", \"accept\" \"/\"}, :server-port 6542, :content-length 19, :content-type \" application/edn\", :character-encoding nil, :uri \"/test-edn\", :server-name \"localhost\", :query-string nil, :body #, :edn-params无， :scheme :http, :request-method :put}"

curl -X PUT -H "Content-Type: application/edn" -d '{:name :barnabasss}' http://localhost:6542/ajax-example

返回：

“请求是：{:ssl-client-cert nil, :remote-addr \"0:0:0:0:0:0:0:1\", :params {:name :barnabasss}, :路由参数 {}, :headers {\"host\" \"localhost:6542\", \"content-length\" \"19\", \"content-type\" \"application/edn\", \"user-agent\" \"curl/7.37.1\", \"accept\" \"/\"}, :server-port 6542, :content-length 19, :content -type \"application/edn\", :character-encoding nil, :uri \"/ajax-example\", :server-name \"localhost\", :query-string nil, :body #, :edn-params {:name :barnabasss}, :scheme :http, :request-method :put}"

在example-routes 中切换它们的顺序，切换哪个有效。谁能解释一下？