Go基础——网络编程

16.1tcp

client

1. 建立与服务端的链接
2. 进行数据收发
3. 关闭链接

func main(){//与服务端建立连接conn, err :&＃61; net.Dial("tcp", "127.0.0.1:20000")if err !&＃61; nil{fmt.Printf("dial failed:%v\n", err)return}input :&＃61; bufio.NewReader(os.Stdin)for{s, err :&＃61; input.ReadString(&＃39;\n&＃39;)if err !&＃61; nil{continue}//去掉空格s &＃61; strings.TrimSpace(s)if strings.ToUpper(s) &＃61;&＃61; "Q"{return}//发消息_, err2 :&＃61; conn.Write([]byte(s))if err !&＃61; nil{fmt.Printf("send failed:%v", err2)return}//从服务端接受回复的消息var buf [1024]byten , err3 :&＃61; conn.Read(buf[:])if err3 !&＃61;nil{fmt.Printf("read failed, %v\n", err3)}fmt.Println("received msg:", string(buf[:n]))}
}


server

1. 监听端口
2. 接收客户端请求建立链接
3. 创建goroutine处理链接。

func process(conn net.Conn){defer conn.Close()//针对当前的链接做数据的发送和接受工作for{reader :&＃61; bufio.NewReader(conn)var buf [128]byten, err :&＃61; reader.Read(buf[:])if err !&＃61; nil{fmt.Printf("err occured :%v\n", err)break}recv :&＃61; string(buf[:n])fmt.Println("receive data:", recv)conn.Write([]byte("ok"))}}func main(){//开启服务listen, err :&＃61; net.Listen("tcp", "127.0.0.1:20000")if err!&＃61;nil{fmt.Printf("err occured:%v\n", err)return}for{//等待客户端来建立链接conn, err :&＃61; listen.Accept()if err !&＃61; nil{fmt.Printf("err occured:%v\n", err)}//启动一个单独的goroutine来处理链接go process(conn)}
}

16.2udp

client

func main(){udp, err :&＃61; net.DialUDP("udp", nil, &net.UDPAddr{IP: net.IPv4(127, 0, 0, 1),Port: 30000,})if err !&＃61; nil{fmt.Println("err occured---", err)return}defer udp.Close()for{input :&＃61; bufio.NewReader(os.Stdin)//fmt.Println("input string:",input)s, _ :&＃61; input.ReadString(&＃39;\n&＃39;)_, err2 :&＃61; udp.Write([]byte(s))if err2 !&＃61; nil{fmt.Println("-err-------")return}//接受数据var buf [1024]byten, addr, err3 :&＃61; udp.ReadFromUDP(buf[:])if err3 !&＃61; nil{fmt.Println("error---:", err3)}fmt.Printf("read from%v, data :%v", addr, string(buf[:n]))}}


server

func main(){listen, err :&＃61; net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4(127, 0, 0, 1),Port: 30000,})if err !&＃61; nil{fmt.Printf("err occured when listen udp:%v", err)}defer listen.Close()for{var buf [1024]byten, addr, err :&＃61; listen.ReadFromUDP(buf[:])if err !&＃61; nil{fmt.Println("err occured when read from udp:", err)return}//接受到的数据fmt.Println("接受到的数据为&＃xff1a;", string(buf[:n]))//返回数据fmt.Println(addr)_, err2 :&＃61; listen.WriteToUDP(buf[:n], addr)if err2 !&＃61; nil{fmt.Printf("err occured:%v", err2)continue}}}