Question

我知道我可以将查询字符串映射为keyworkd地图。

(defroutes my-routes
  (GET "/" {params :query-params} params))

但有没有办法用字符串键控地图做同样的事情？（使用Compojure或Ring ）

这里的要点不是迭代地图或使用函数，但默认情况下使用字符串键创建。

{ :a "b" } -> {"a" "b"}

Answer 1

Compojure 1.5.1默认不解析任何查询字符串（不使用任何中间件）。但是，在早期版本中可能会有所不同。

(require '[compojure.core :refer :all])
(require '[clojure.pprint :refer [pprint]])

(defroutes handler
  (GET "/" x
       (with-out-str (pprint x)))) ;; just a way to receive a pretty printed string response

$ curl localhost:3000/?a=b
{:ssl-client-cert nil,
 :protocol "HTTP/1.1",
 :remote-addr "127.0.0.1",
 :params {},  ;; EMPTY!
 :route-params {},
 :headers
 {"user-agent" "curl/7.47.1", "accept" "*/*", "host" "localhost:3000"},
 :server-port 3000,
 :content-length nil,
 :compojure/route [:get "/"],
 :content-type nil,
 :character-encoding nil,
 :uri "/",
 :server-name "localhost",
 :query-string "a=b",  ;; UNPARSED QUERY STRING
 :body
 #object[org.eclipse.jetty.server.HttpInputOverHTTP 0x6756d3a3 "HttpInputOverHTTP@6756d3a3"],
 :scheme :http,
 :request-method :get}

Ring提供ring.params.wrap-params中间件，它解析查询字符串并在params-key下创建它的hashmap：

(defroutes handler
  (wrap-params (GET "/" x
                 (prn-str (:params x)))))

$ curl localhost:3000/?a=55
{"a" "55"}

可以使用Additionaly ring.params.wrap-params：

(defroutes handler
  (wrap-params (wrap-keyword-params (GET "/" x
                                     (prn-str (:params x))))))

$ curl localhost:3000/?a=55
{:a "55"}

Answer 2

不确定compojure，但您可以自行撤消：

(use 'clojure.walk)

(stringify-keys {:a 1 :b {:c {:d 2}}}) 
;=> {"a" 1, "b" {"c" {"d" 2}}}

https://clojuredocs.org/clojure.walk/stringify-keys

Compojure - 使用字符串键映射查询参数

2 个答案: