Micro-credit Payment-golang backend processing

This is a creation in Article, where the information may have evolved or changed.

First, the payment process

Open platform H5 payment access RELATED links: Https://pay.weixin.qq.com/wiki/doc/api/H5.php?chapter=15_4

The corresponding payment process:

Second, the relevant code

1, the Unified order

First define a unifyorderreq to fill in the parameters we want to pass in.

Type unifyorderreq struct {

Appid            string ' xml: ' Appid '

Body             string ' xml: ' body '

mch_id           string ' xml: ' mch_id '

Nonce_str        string ' xml: ' Nonce_str '

Notify_url       string ' xml: ' Notify_url '

Trade_type       string ' xml: ' Trade_type '

SPBILL_CREATE_IP string ' xml: ' Spbill_create_ip '

Total_fee        int    ' xml: "Total_fee" '

Out_trade_no     string ' xml: ' Out_trade_no '

Sign             string ' xml: ' sign '

}

Wxpay function for calculating signatures

Func (o *apihandler) wxpaycalcsign (Mreq map[string]interface{}, key String) (sign string) {

Log4go. Debug ("Wxpaycalcsign () ... API key:%s ", KEY)

STEP 1, sort the key in ascending order.

Sorted_keys: = Make ([]string, 0)

For k, _: = Range Mreq {

Sorted_keys = Append (Sorted_keys, k)

}

Sort. Strings (Sorted_keys)

STEP2, the key value pair of Key=value is connected with &, slightly over null value.

var signstrings string

For _, K: = Range Sorted_keys {

Fmt. Printf ("K=%v, v=%v\n", K, Mreq[k])

Value: = FMT. Sprintf ("%v", Mreq[k])

if value! = "" {

Signstrings = signstrings + k + "=" + Value + "&"

}

}

STEP3, at the end of the key-value pair, plus Key=api_key

If key! = "" {

Signstrings = signstrings + "key=" + key

}

Log4go. Debug ("Wxpaycalcsign () signstrings:%s", signstrings)

STEP4, make MD5 signature and capitalize all characters.

MD5CTX: = MD5. New ()

Md5ctx.write ([]byte (Signstrings))

CIPHERSTR: = Md5ctx.sum (nil)

Uppersign: = Strings. ToUpper (Hex. Encodetostring (CIPHERSTR))

Return uppersign

}

Func (o *apihandler) wxunifychargereq (userId int64, OrderNo string) (string, error) {

Log4go. Debug ("Wxunifychargereq () userid:%d, orderno:%s", UserId, OrderNo)

Bookorder, err: = O.getorderbyordernodb (OrderNo)

If err! = Nil {

Log4go. Error ("Wxunifychargereq (): Getorderbyordernodb error.")

Return "", err

}

NONCESTR: = getrandomstring (32)

Code to request Unifiedorder

var yourreq unifyorderreq

Yourreq.appid = wx_app_id//Open Platform app ID of the app we created

Yourreq.body = Bookorder.linenum

yourreq.mch_id = wx_mch_id

Yourreq.nonce_str = Noncestr

Yourreq.notify_url = Wx_notify_url

Yourreq.trade_type = "APP"

YOURREQ.SPBILL_CREATE_IP = Wx_invoke_api_ip

Yourreq.total_fee = Int (bookorder.totalprice * 100)//Unit is divided

Yourreq.out_trade_no = OrderNo

var m map[string]interface{}

m = Make (map[string]interface{}, 0)

m["AppID"] = Yourreq.appid

m["Body"] = Yourreq.body

m["mch_id"] = yourreq.mch_id

m["Notify_url"] = Yourreq.notify_url

m["Trade_type"] = Yourreq.trade_type

m["spbill_create_ip"] = Yourreq.spbill_create_ip

m["Total_fee"] = Yourreq.total_fee

m["out_trade_no"] = Yourreq.out_trade_no

m["nonce_str"] = Yourreq.nonce_str

Yourreq.sign = O.wxpaycalcsign (M, Wx_pay_key)//This is the function that calculates the wxpay signature that has been posted

Bytes_req, err: = XML. Marshal (Yourreq)

If err! = Nil {

Log4go. Error ("Wxunifychargereq (): XML. Marshal error:%s ", err)

Return "", err

}

Str_req: = String (bytes_req)

Wxpay Unifiedorder interface requires HTTP body xmldoc root node is <xml></xml> this, so here need to replace a bit

Str_req = strings. Replace (Str_req, "Xunifyorderreq", "xml",-1)

Bytes_req = []byte (str_req)

Log4go. Debug ("Wxunifychargereq () str_req:%s", Str_req)

Send unified order Request.

Req, Err: = http. Newrequest ("POST", Wx_unifiedorder_api, Bytes. Newreader (Bytes_req))

If err! = Nil {

Log4go. Error ("wxunifychargereq (): http. Newrequest error:%s ", err)

Return "", err

}

Req. Header.set ("Accept", "Application/xml")

The settings for the HTTP header here must be set.

Req. Header.set ("Content-type", "Application/xml;charset=utf-8")

c: = http. client{}

RESP, _err: = C.do (req)

If _err! = Nil {

Log4go. Error ("wxunifychargereq (): http. Do error:%s ", _err)

Return "", err

}

Defer resp. Body.close ()

Body, err: = Ioutil. ReadAll (resp. Body)

Retxml: = string (body)

Log4go. Debug ("Wxunifychargereq () retxml:%s", Retxml)

If err! = Nil {

Return "", err

}

Return Retxml, Nil

}

2. Verification (to be continued)