采用技术，Go、channel、协程、redis、websocket
package model

import (
"encoding/json"
"fmt"
"github.com/gorilla/websocket"
"gorm.io/gorm"
"net"
"net/http"
"strconv"
"sync"
)

//消息
type Message struct {
gorm.Model
FormId int64 //发送者
TargetId int64 //接收者
Type int //私聊、群聊、广播 消息类型
Media int //消息类型 文字、图片、音频
Content string //消息内容
Pic string
Url string
Desc string //描述
Amount int //数字统计
}

//人员关系
type Contact struct {
gorm.Model
OwnerId uint //谁的关系
TargetId uint //对应的谁
Type int //关系类型
Desc string //描述
}

//群
type GroupBasic struct {
gorm.Model
Nmae string
OwnerId uint
Type int
Icon string //图标
Desc string
}

type Node struct {
Conn *websocket.Conn
DataQuene chan []byte
//GroupSets set.Interface
}

//映射关系
var clientMap map[int64]Node = make(map[int64]Node, 0)

//读写锁
var rwLocker sync.RWMutex

func Chat(write http.ResponseWriter, request *http.Request) {

//校验Token
query := request.URL.Query()
Id := query.Get("userId")
//token := query.Get("token")
//targetId := query.Get("targetId")
userid, _ := strconv.ParseInt(Id, 10, 64)
//context := query.Get("context")
//msgtype := query.Get("type")
conn, err := (&websocket.Upgrader{
    CheckOrigin: func(r *http.Request) bool {
        return true
    },
}).Upgrade(write, request, nil)
if err != nil {
    fmt.Println(err)
    return
}
//获取连接
node := &Node{
    Conn:      conn,
    DataQuene: make(chan []byte, 50),
}
//用户关系

//userid与node绑定,并加锁
rwLocker.Lock()
clientMap[userid] = node
rwLocker.Unlock()

//完成发送逻辑
go SendProc(node)
//完成接收逻辑
go WriteProc(node)
sendMsg(userid, []byte("欢迎进入"))

}

func SendProc(node *Node) {
for {
select {
case data := <-node.DataQuene:
err := node.Conn.WriteMessage(websocket.TextMessage, data)
if err != nil {
fmt.Println(err)
return
}
}
}
}

func WriteProc(node *Node) {
for {
_, data, err := node.Conn.ReadMessage()
if err != nil {
fmt.Println(err)
return
}
broadMsg(data)
fmt.Println("[ws]------", data)
}
}

var udpsendChan chan []byte = make(chan []byte, 1024)

func broadMsg(data []byte) {
//把要发送的消息放进通道里面
udpsendChan <- data
}

func init() {
go udpSendProc()
go udpWriteProc()
}

//完成数据udp的发送协程
func udpSendProc() {
con, err := net.DialUDP("udp", nil, &net.UDPAddr{
IP: net.IPv4(10, 102, 0, 255),
Port: 3000,
})
defer con.Close()
if err != nil {
fmt.Println(err)
return
}
for {
select {
case data := <-udpsendChan:
_, err = con.Write(data)
if err != nil {
fmt.Println(err)
return
}
}
}
}

//完成udp数据接收协程
func udpWriteProc() {
con, err := net.ListenUDP("udp", &net.UDPAddr{
IP: net.IPv4zero,
Port: 3000,
})
if err != nil {
fmt.Println(err)
return
}
defer con.Close()
for {
var buf [512]byte
n, err := con.Read(buf[0:])
if err != nil {
fmt.Println(err)
return
}
dispatch(buf[0:n])
}
}

//后端调度逻辑处理
func dispatch(data []byte) {
msg := Message{}
err := json.Unmarshal(data, &msg)
if err != nil {
fmt.Println(err)
return
}
switch msg.Type {
case 1: //私信
sendMsg(msg.TargetId, data)
//case 2://群发
// sendGroupMsg()
//case 3:
// sendAllMsg()
//case 4:

}

}
func sendMsg(userId int64, msg []byte) {
//上锁
rwLocker.RLock()
node, ok := clientMap[userId]
//解锁
rwLocker.RUnlock()
if ok {
node.DataQuene <- msg
}
}