Question

修改online example，我具有以下代码，该代码允许对此Racket网络服务器发出http请求；

#lang racket

(require web-server/servlet) 
(require web-server/servlet-env)

(define (http-response content)  
  (response/full
    200                  ; HTTP response code.
    #"OK"                ; HTTP response message.
    (current-seconds)    ; Timestamp.
    TEXT/HTML-MIME-TYPE  ; MIME type for content.
    '()                  ; Additional HTTP headers.
    (list                ; Content (in bytes) to send to the browser.
      (string->bytes/utf-8 content))))

(define (show-time-page request)
  (http-response (number->string (current-seconds))))

(define (greeting-page request)  
  (http-response (list-ref '("Hi" "Hello") (random 2))))

 (define get-data ...)

;; URL routing table (URL dispatcher).
(define-values (dispatch generate-url)
  (dispatch-rules
    [("time") show-time-page]
    [("hello") greeting-page]  ; Notice this line.
    [else (error "There is no procedure to handle the url.")]))

(define (request-handler request)
  (dispatch request))

;; Start the server.
(serve/servlet
  request-handler
  #:launch-browser? #f
  #:quit? #f
  #:listen-ip "127.0.0.1"
  #:port 8001
  #:servlet-regexp #rx"")

如何更改以上代码，以使其能够通过http请求接收发布到Racket网络服务器的数据（例如字符串）并在控制台中显示？请您帮忙？

Answer 1

为POST请求定义一个请求处理程序。让它从request中提取发布的数据：

(define (example-post request)
  (define data (request-post-data/raw request))
  (define str (format "got post data: ~v" data))
  (displayln str)
  (http-response str))

将处理程序添加到dispatch-rules。确保指定它正在处理POST（不是默认的GET）请求：

;; URL routing table (URL dispatcher).
(define-values (dispatch generate-url)
  (dispatch-rules
    [("time") show-time-page]
    [("hello") greeting-page]
    [("example-post") #:method "post" example-post] ; <=== NEW
    [else (error "There is no procedure to handle the url.")]))

现在，如果需要，在外壳中

curl --data "hi" http://127.0.0.1:8001/example-post

它将显示响应数据got post data: #"hi" ---和Racket控制台一样。

如何将数据发送到Racket服务器？

1 个答案: