golang实现微信公众号发红包功能

淡淡的烟草味﹌ 2022-06-08 12:56 207阅读 0赞

**ps：在读代码前一定要先阅读微信公众号发红包官方文档：**

https://pay.weixin.qq.com/wiki/doc/api/tools/cash\_coupon.php?chapter=13\_4&index=3

以下是代码实现，

package server
    
    import (
    	"crypto/tls"
    	"fmt"
    	"io/ioutil"
    	"crypto/x509"
    	"net/http"
    	"bytes"
    	"strings"
    	"sort"
    	"reflect"
    	"time"
    	"math/rand"
    	"strconv"
    	"encoding/xml"
    	"github.com/alecthomas/log4go"
    	"crypto/md5"
    	"encoding/hex"
    )
    
    var _tlsConfig *tls.Config
    var (
    	weixinPayKey="19200bbb0b4c09247ec02edce69f6ddd"   //微信密钥
    	weixinMchId = "10000098"  //微信商户号
    	wechatUrl = "https://api.mch.weixin.qq.com/mmpaymkttransfers/sendredpack"  //请求发红包的地址
    	formatDate = "20060102"
    	xmlStr = "xml"
    	RedPacketRequestStr = "RedPacketRequest"
    	strWeixinAppId =            "wx8888888888888888"         //公众账号ID
    	strWeixinClientCertPemPath = "/home/apiclient_cert.pem"  //客户端证书存放绝对路径
    	strWeixinClientKeyPemPath = "/home/apiclient_key.pem"    //客户端私匙存放绝对路径
    	strWeixinRootCaPath = "/home/rootca.pem"                 //服务端证书存放绝对路径
    )
    
    type WeixinSendRedPacket struct {
    
    }
    
    
    //发红包的请求实体
    type RedPacketRequest struct {
    	ActName  	string      `xml:"act_name"`	  //必填，活动名称
    	ClientIp 	string 		`xml:"client_ip"`	  //必填，调用接口的机器ip地址
    	MchBillno 	string  	`xml:"mch_billno"`   //必填，商户订单号
    	MchId    	string		`xml:"mch_id"`       //必填，微信支付分配的商户号
    	NonceStr  	string  	`xml:"nonce_str"`    //必填,随机字符串，不超过32位
    	ReOpenid  	string   	`xml:"re_openid"`	  //必填，接收红包者用户，用户在wxappid下的openid
    	Remark		string      `xml:"remark"`		  //必填，备注信息
    	SendName  	string		`xml:"send_name"`    //必填，红包发送者名称
    	TotalAmount int		  	`xml:"total_amount"` //必填，付款金额，单位为分
    	TotalNum    int 		`xml:"total_num"`    //必填，红包发放人数
    	Wishing     string 		`xml:"wishing"`      //必填，红包祝福语
    	Wxappid  	string		`xml:"wxappid"`      //必填，微信公众号id
    	Sign      	string  	`xml:"sign"`		  //必填，签名
    	//SceneId		string		`xml:"scene_id"`	  //非必填，红包使用场景
    	//RiskInfo 	string		`xml:"risk_info"`    //非必填，用户操作的时间戳
    	//ConsumeMchId string		`xml:"consume_mch_id"` //非必填，资金授权商户号
    }
    
    
    
    //发微信红包
    func (*WeixinSendRedPacket)SendRedPack(redPacketEntity *RedPacketRequest) (*http.Response, error) {
    	nonce_str,_ := getUUID()   //随机字符串
    
    	//订单号,随机生成
    	r := rand.New(rand.NewSource(time.Now().UnixNano()))
    	mch_billno:=weixinMchId + time.Now().Format(formatDate) + strconv.FormatInt(time.Now().Unix(), 10)[4:]+strconv.Itoa(r.Intn(8999) + 1000)
    
    	redPacketEntity.NonceStr=nonce_str
    	redPacketEntity.MchBillno=mch_billno
    	redPacketEntity.MchId=weixinMchId
    	redPacketEntity.Wxappid = strWeixinAppId
    	// 生成签名
    	sign := strings.ToUpper(signature(*redPacketEntity)) //签名
    	redPacketEntity.Sign=sign
    
    	data, err := xml.MarshalIndent(redPacketEntity, "", "   ")
    
    	if err!=nil {
    		log4go.Error(err)
    		return nil,err
    	}
    	sendData:=strings.Replace(string(data), RedPacketRequestStr , xmlStr ,-1)
    
    	fmt.Println(sendData)
    	//POST数据
    	return securePost(wechatUrl, []byte(sendData))
    }
    
    //加载微信发红包需要的证书
    func getTLSConfig() (*tls.Config, error) {
    	if _tlsConfig != nil {
    		return _tlsConfig, nil
    	}
    
    	// load cert
    	cert, err := tls.LoadX509KeyPair(strWeixinClientCertPemPath, strWeixinClientKeyPemPath)
    	if err != nil {
    		fmt.Println("load wechat keys fail", err)
    		return nil, err
    	}
    
    	// load root ca
    	caData, err := ioutil.ReadFile(strWeixinRootCaPath)
    	if err != nil {
    		fmt.Println("read wechat ca fail", err)
    		return nil, err
    	}
    	pool := x509.NewCertPool()
    	pool.AppendCertsFromPEM(caData)
    
    	_tlsConfig = &tls.Config{
    		Certificates: []tls.Certificate{cert},
    		RootCAs:      pool,
    	}
    	return _tlsConfig, nil
    }
    
    //http发送请求
    func securePost(url string, xmlContent []byte) (*http.Response, error) {
    	tlsConfig, err := getTLSConfig()
    	if err != nil {
    		return nil, err
    	}
    
    	tr := &http.Transport{TLSClientConfig: tlsConfig}
    	client := &http.Client{Transport: tr}
    
    	return client.Post(
    		url,
    		"text/xml",
    		bytes.NewBuffer(xmlContent))
    }
    
    
    //签名算法
    func signature(sendParamEntity interface{}) string {
    	str:=getFieldString(sendParamEntity)
    	if str!=""{
    		str=fmt.Sprintf("%s&%s=%s",str,"key",weixinPayKey)
    		fmt.Println(str)
    		md5Ctx2 := md5.New()
    		md5Ctx2.Write([]byte(str))
    		str = hex.EncodeToString(md5Ctx2.Sum(nil))
    
    		return str
    	}else{
    		return ""
    	}
    }
    
    //获取结构体字段及值的拼接值
    func getFieldString(sendParamEntity interface{}) string {
    	m:=reflect.TypeOf(sendParamEntity)
    	v:=reflect.ValueOf(sendParamEntity)
    	var tagName string
    	numField:=m.NumField()
    	w:=make([]string,numField)
    	numFieldCount:=0
    	for i := 0; i < numField; i++ {
    		fieldName:=m.Field(i).Name
    		tags := strings.Split(string(m.Field(i).Tag), "\"")
    		if len(tags) > 1 {
    			tagName = tags[1]
    		} else {
    			tagName = m.Field(i).Name
    		}
    
    		fieldValue:=v.FieldByName(fieldName).Interface()
    
    		if fieldValue!=""  {
    			s:=fmt.Sprintf("%s=%v",tagName,fieldValue)
    			w[numFieldCount]=s
    			numFieldCount++
    		}
    	}
    	if numFieldCount==0{
    		return ""
    	}
    	w = w[:numFieldCount]
    	sort.Strings(w)
    	return strings.Join(w,"&")
    }
    
    //获取uuid
    func getUUID() (string, error) {
    	uuid := make([]byte, 16)
    	n, err := rand.Read(uuid)
    	if n != len(uuid) || err != nil {
    		return "", err
    	}
    	uuid[8] = 0x80 // variant bits see page 5
    	uuid[4] = 0x40 // version 4 Pseudo Random, see page 7
    
    	return hex.EncodeToString(uuid), nil
    }