openresty 學習筆記二:獲取請求數據

openresty 獲取POST或者GET的請求參數。這個是要用openresty 做接口必須要做的事情。
這里分幾種類型：GET，POST(urlencoded),POST(form-data)。可以根據需要選擇某種提交請求的方式，也可以集合封裝成一個工具庫來使用

GET 請求

GET的請求數據比較簡單

function _M.get(self)
    local  getArgs = {}
    getArgs = ngx.req.get_uri_args()
    return getArgs
end

　　

POST(urlencoded) 請求

urlencoded類型的POST請求數據也比較簡單

function _M.post_urlencoded(self)
    local  postArgs = {}
    postArgs = ngx.req.get_post_args()
    return postArgs
end

　　

POST(form-data) 請求

form-data類型的POST請求數據就比較復雜，需要進行字符串分割(lua好像不帶split方法)，所以首先要寫一個split方法

function _M.split(self,s, delim)

    if type(delim) ~= "string" or string.len(delim) <= 0 then
        return nil
    end
 
    local start = 1
    local t = {}

    while true do
        local pos = string.find (s, delim, start, true) -- plain find
        
        if not pos then
            break
        end
 
        table.insert (t, string.sub (s, start, pos - 1))
        start = pos + string.len (delim)
    end

    table.insert (t, string.sub (s, start))
 
    return t
end

　　

獲取form-data的請求參數需要用到upload庫來獲取表單，這個庫安裝openresty默認已經帶了，也可以上GITHUB下載最新版本

local upload = require "resty.upload"
local form, err = upload:new(4096)

function _M.post_form_data(self,form,err)

    if not form then
        ngx.log(ngx.ERR, "failed to new upload: ", err)
        return {}
    end

    form:set_timeout(1000) -- 1 sec
    local paramTable = {["s"]=1}
    local tempkey = ""
    while true do
        local typ, res, err = form:read()
        if not typ then
            ngx.log(ngx.ERR, "failed to read: ", err)
            return {}
        end
        local key = ""
        local value = ""
        if typ == "header" then
            local key_res = _M:split(res[2],";")
            key_res = key_res[2]
            key_res = _M:split(key_res,"=")
            key = (string.gsub(key_res[2],"\"",""))
            paramTable[key] = ""
            tempkey = key
        end
        if typ == "body" then
            value = res
            if paramTable.s ~= nil then paramTable.s = nil end
            paramTable[tempkey] = value
        end
        if typ == "eof" then
            break
        end
    end
    return paramTable
end

args = _M:post_form_data(form, err)

　　

根據請求類型不同使用不同方法進行獲取

根據需要，也可以將其合並起來

• function _M.new()
      local args = {}
      local requestMethod = ngx.var.request_method
      local receiveHeaders = ngx.req.get_headers()
      local upload = require "resty.upload"
      local form, err = upload:new(chunk_size)
  
      if "GET" == requestMethod then
          args = _M:get()
      elseif "POST" == requestMethod then
          ngx.req.read_body()
          if string.sub(receiveHeaders["content-type"],1,20) == "multipart/form-data;" then
              args = _M:post_form_data(form, err)
          else
              args = _M:post_urlencoded()
          end
      end
  
      return args
  end
  
  return _M