golang 之UDP

udp server

package main

import (
    "bufio"
    "fmt"
    "net"
    "os"
    "strings"
)

func putaway(conn *net.UDPConn)(addr *net.UDPAddr){
    var data [1024]byte
    n,addr,err := conn.ReadFromUDP(data[:])
    if err != nil{
        fmt.Println("read form UDP failed err:",err)
        return
    }
    fmt.Print(strings.ToUpper(string(data[:n])))
    // //转换成大写
    // reply := strings.ToUpper(string(data[:n]))
    // conn.WriteToUDP([]byte(reply),addr)
    return addr
}

func sendData(conn *net.UDPConn, addr *net.UDPAddr){
    reader := bufio.NewReader(os.Stdin)
    fmt.Print("请输入:")
    msg,_ := reader.ReadString('\n')
    conn.WriteToUDP([]byte(msg),addr)
}
//UDP server
func main(){
    conn,err := net.ListenUDP("udp",&net.UDPAddr{
        IP: net.IPv4(127,0,0,1),
        Port: 40000,
    })
    if err !=nil{
        fmt.Println("listen UDP failed,err",err)
        return
    }
    defer conn.Close()
    //不需要建立链接，直接接收数据
    
    //
    for {
        //接收数据
        addr := putaway(conn)
        //终端输入发送数据
        sendData(conn,addr)
    }
}

udp client

package main

import (
    "bufio"
    "fmt"
    "net"
    "os"
)


//UDP client

func main(){
    socket ,err := net.DialUDP("udp",nil ,&net.UDPAddr{
        IP: net.IPv4(127,0,0,1),
        Port: 40000,
    })
    if err !=nil{
        fmt.Println("连接服务器失败， err ",err)
        return
    }
    defer socket.Close()
    var reply [1024]byte
    reader := bufio.NewReader(os.Stdin)
    for {
        fmt.Print("请输入:")
        msg,_ := reader.ReadString('\n')
        socket.Write([]byte(msg))
        //收回复的数据
        n , _ , err :=socket.ReadFromUDP(reply[:])
        if err !=nil{
            fmt.Println("redv reply msg failed err",err)
            return
        } 
        fmt.Println("收到回复信息:", string(reply[:n]))
    }

}