golang中的udp编程

1. udp server

package main
 
import (
    "fmt"
    "net"
)
 
func main() {
 
    // udp server
    listenUdp, err := net.ListenUDP("udp", &net.UDPAddr{
        IP:   net.IPv4(127,0,0,1),
        Port: 8080,
    })
    if err != nil {
        fmt.Println("ListenPacket fail err", err)
        return
    }
    defer listenUdp.Close()
 
    for {
        // 接收数据
        var buf [1024]byte
        n, addr, err := listenUdp.ReadFromUDP(buf[:])
        if err != nil {
            fmt.Println("ReadFromUDP fail err", err)
            continue
        }
        fmt.Printf("接收到客户端【%v】的数据：%s\n", addr, string(buf[:n]))
 
        // 发送数据
        msg := "server发送回来的数据" + string(buf[:n])
        num, err := listenUdp.WriteToUDP([]byte(msg), addr)
        if err != nil {
            fmt.Println("WriteToUDP fail err", num, err)
            continue
        }
 
    }
 
}

2. udp client

package main
 
import (
    "fmt"
    "net"
    "strings"
)
 
func main() {
    // udp client
    udpConn, err := net.DialUDP("udp", nil, &net.UDPAddr{
        IP:   net.IPv4(127,0,0,1),
        Port: 8080,
    })
    if err != nil {
        fmt.Println("DialUDP fail err", err)
        return
    }
 
    defer udpConn.Close()
 
    for {
        // 发送数据
        var data string
        fmt.Print("请输入要发送给服务器的数据：")
        fmt.Scanln(&data)
        if strings.ToUpper(data) == "Q" {
            break
        }
        sendData := []byte(data)
        _, err = udpConn.Write(sendData)
        if err != nil {
            fmt.Println("udp客户端Write fail err", err)
            return
        }
 
        // 接收数据
        buf := make([]byte, 4096)
        n, remoteAddr, err2 := udpConn.ReadFromUDP(buf[:])
        if err2 != nil {
            fmt.Println("udp客户端Read fail err", err2)
            return
        }
        fmt.Printf("data：%v, addr：%v\n", string(buf[:n]), remoteAddr)
 
    }
}