看了两天 go 语言,是时候练练手了。
go 的 routine(例程) 和 chan(通道) 简直是神器,实现多线程(在 go 里准确的来说是 多例程)简直不要太轻松。
于是动手码了一个傻瓜版的黑框聊天器。
server 端:
监听 TCP 连接;支持自定义客户端命令;支持消息分发;理论上支持广播;...
package main
import (
"fmt"
"net"
"io"
"strconv"
"time"
"strings"
)
const (
NORMAL_MESSAGE = iota
LIST_MESSAGE
)
var clientSenders = make(map[string] chan string)
func send (addr string, conn *net.Conn){
senderChan := clientSenders[addr]
for s := range senderChan{
(*conn).Write([]byte(s))
}
}
func sendUsersInfo(addr string){
senderChan := clientSenders[addr]
if nil != senderChan{
ls := strconv.Itoa(LIST_MESSAGE)
cs := strconv.Itoa(NORMAL_MESSAGE) + "已登录客户端列表:\n"
i := 1
for k := range clientSenders{
a := ""
if k == addr {
a = "(我)"
}
cs = cs + strconv.Itoa(i) + ")" + k + a + "\n"
ls += k + "\n"
i ++
}
cs += "发送消息,可使用 1<-这是给1号客户端的消息\n(请使用英文以获取最佳体验)\n"
senderChan <- cs
time.Sleep(time.Millisecond * 300)
senderChan <- ls
// 发送格式化的列表
fmt.Println("已发送“登录用户信息”", addr)
} else{
fmt.Println("客户端接受通道不存在", addr)
}
}
func serve (conn *net.Conn){
connect := *conn
addr := connect.RemoteAddr().String()
fmt.Println(addr, "接入服务")
senderChan := make(chan string, 3)
clientSenders[addr] = senderChan
// 启动发送
go send(addr, conn)
// 发送当前用户信息
go sendUsersInfo(addr)
buff := make([]byte, 10240)
for {
n, err := connect.Read(buff)
if err != nil {
if err == io.EOF {
fmt.Println("客户端断开链接,", addr)
delete(clientSenders, addr)
return
} else{
fmt.Println(err)
}
}
msg := string(buff[:n])
// 刷新客户端列表
if msg == "ls\n" {
go sendUsersInfo(addr)
continue
}
// 提取数据
msgs := strings.Split(msg, "<-")
if len(msg) < 2{
senderChan <- string("数据格式不正确,请联系开发者")
continue
}
aimAddr := msgs[0]
aimSender := clientSenders[aimAddr]
if aimSender == nil {
senderChan <- string("客户端已下线,使用 ls 命令获取最新的客户端列表")
continue
}
aimSender <- strconv.Itoa(NORMAL_MESSAGE) + "[from:" + addr + "]:" + strings.Join(msgs[1:], "<-")
}
}
func main(){
addr := ":8080"
listener, err := net.Listen("tcp", addr)
if err != nil{
fmt.Println(err)
return
}
// 启动消息调度器
defer listener.Close()
// 启动连接监听
for {
conn, err := listener.Accept()
if err != nil {
fmt.Println(err)
continue
}
go serve(&conn)
}
}
客户端:
支持断线重连;支持给特定其他客户端发信息
package main
import (
"net"
"fmt"
"io"
"os"
"bufio"
"sync"
"time"
"strings"
"strconv"
)
var conn *net.Conn
var addrs []string
const (
NORMAL_MESSAGE = iota
LIST_MESSAGE
)
func read(conn2 *net.Conn){
defer func() {
fmt.Println("尝试重连")
go connectServer()
}()
connect := *conn2
buff := make([]byte, 20140)
for {
n, err := connect.Read(buff)
if err != nil {
if err == io.EOF{
fmt.Println("结束")
(*conn2).Close()
conn = nil
return
} else{
fmt.Println(err)
}
}
msg := string(buff[:n])
t, err := strconv.Atoi(string(msg[0]))
msg = msg[1:]
switch t {
case NORMAL_MESSAGE:
fmt.Print(msg)
break
case LIST_MESSAGE:
// 解析客户端列表数据
addrs = strings.Split(msg, "\n")
fmt.Println("已接收客户端列表。\n")
break
default:
fmt.Print(msg)
break
}
}
}
func connectServer(){
addr := "192.168.99.236:8080"
fmt.Println("等待服务器开启中")
conn2, err := net.Dial("tcp", addr)
if err != nil {
fmt.Print(err)
fmt.Println("连接失败,10s后尝试")
time.Sleep(10 * time.Second)
go connectServer()
return
}
fmt.Println("已连接")
conn = &conn2
go read(&conn2)
}
func send (){
inputReader := bufio.NewReader(os.Stdout)
for {
input, err := inputReader.ReadString('\n')
if err != nil {
if err == io.EOF{
return
} else{
fmt.Println(err)
}
}
if input == "ls\n" {
(*conn).Write([]byte(input))
continue
}
msgs := strings.Split(input, "<-")
if len(msgs) < 2 {
fmt.Println("发送的姿势不正确,应该像这样 1<-给1号发送消息\n")
continue
}
index, err := strconv.Atoi(msgs[0])
if err != nil {
fmt.Println("发送的姿势不正确,应该像这样 1<-给1号发送消息\n")
continue
}
if len(addrs) <= index {
fmt.Println("不存在第" + strconv.Itoa(index) + "个客户端\n")
continue
}
addr := addrs[index-1]
input = addr + "<-" + strings.Join(msgs[1:], "<-")
if nil != conn {
(*conn).Write([]byte(input))
}
}
}
func main (){
var wg sync.WaitGroup
wg.Add(2)
go connectServer()
go send()
wg.Wait()
defer func() {
if nil != conn {
(*conn).Close()
}
}()
}
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