Nginx服务器中使用lua获取get或post参数

使用ngx_lua模块(http://wiki.nginx.org/HttpLuaModule)：
local request_method = ngx.var.request_method
local args = nil
local param = nil
local param2 = nil
--获取参数的值
if "GET" == request_method then
    args = ngx.req.get_uri_args()
elseif "POST" == request_method then
    ngx.req.read_body()
    args = ngx.req.get_post_args()
end
param = args["param"]
param2 = args["param2"]
升级版(能处理content-type=multipart/form-data的表单)：
local function explode ( _str,seperator )
        local pos, arr = 0, {}
                for st, sp in function() return string.find( _str, seperator, pos, true ) end do
                        table.insert( arr, string.sub( _str, pos, st-1 ) )
                        pos = sp + 1
                end
        table.insert( arr, string.sub( _str, pos ) )
        return arr
end
local args = {}
local file_args = {}
local is_have_file_param = false
local function init_form_args()
        local receive_headers = ngx.req.get_headers()
        local request_method = ngx.var.request_method
        if "GET" == request_method then
                args = ngx.req.get_uri_args()
        elseif "POST" == request_method then
                ngx.req.read_body()
                if string.sub(receive_headers["content-type"],1,20) == "multipart/form-data;" then--判断是否是multipart/form-data类型的表单
                        is_have_file_param = true
                        content_type = receive_headers["content-type"]
                        body_data = ngx.req.get_body_data()--body_data可是符合http协议的请求体，不是普通的字符串
                        --请求体的size大于nginx配置里的client_body_buffer_size，则会导致请求体被缓冲到磁盘临时文件里，client_body_buffer_size默认是8k或者16k
                        if not body_data then
                                local datafile = ngx.req.get_body_file()
                                if not datafile then
                                        error_code = 1
                                        error_msg = "no request body found"
                                else
                                        local fh, err = io.open(datafile, "r")
                                        if not fh then
                                                error_code = 2
                                                error_msg = "failed to open " .. tostring(datafile) .. "for reading: " .. tostring(err)
                                        else
                                                fh:seek("set")
                                                body_data = fh:read("*a")
                                                fh:close()
                                                if body_data == "" then
                                                        error_code = 3
                                                        error_msg = "request body is empty"
                                                end
                                        end
                                end
                        end
                        local new_body_data = {}
                        --确保取到请求体的数据
                        if not error_code then
                                local boundary = "--" .. string.sub(receive_headers["content-type"],31)
                                local body_data_table = explode(tostring(body_data),boundary)
                                local first_string = table.remove(body_data_table,1)
                                local last_string = table.remove(body_data_table)
                                for i,v in ipairs(body_data_table) do
                                        local start_pos,end_pos,capture,capture2 = string.find(v,'Content%-Disposition: form%-data; name="(.+)"; filename="(.*)"')
                                        if not start_pos then--普通参数
                                                local t = explode(v,"\r\n\r\n")
                                                local temp_param_name = string.sub(t[1],41,-2)
                                                local temp_param_value = string.sub(t[2],1,-3)
                                                args[temp_param_name] = temp_param_value
                                        else--文件类型的参数，capture是参数名称，capture2是文件名
                                                file_args[capture] = capture2
                                                table.insert(new_body_data,v)
                                        end
                                end
                                table.insert(new_body_data,1,first_string)
                                table.insert(new_body_data,last_string)
                                --去掉app_key,app_secret等几个参数，把业务级别的参数传给内部的API
                                body_data = table.concat(new_body_data,boundary)--body_data可是符合http协议的请求体，不是普通的字符串
                        end
                else
                        args = ngx.req.get_post_args()
                end
        end
end