package main
 
import (
    "fmt"
    "net"
)
 
func main() {
    //1.建立監(jiān)聽端口
    listen, err := net.Listen("tcp", "0.0.0.0:20000")
    if err != nil {
        fmt.Println("listen failed, err:", err)
        return
    }
 
    fmt.Println("listen Start...:")
 
    for {
        //2.接收客戶端的鏈接
        conn, err := listen.Accept()
        if err != nil {
            fmt.Printf("accept failed, err:%v\n", err)
            continue
        }
        //3.開啟一個Goroutine，處理鏈接
        go process(conn)
    }
}
 
//處理請求，類型就是net.Conn
func process(conn net.Conn) {
 
    //處理結(jié)束后關(guān)閉鏈接
    defer conn.Close()
    for {
        var buf [128]byte
        n, err := conn.Read(buf[:])
        if err != nil {
            fmt.Printf("read from conn failed, err:%v", err)
            break
        }
        fmt.Printf("recv from client, content:%v\n", string(buf[:n]))
    }
 
}

2.客戶端處理流程

a.和服務(wù)端建立一個鏈接
b.進行數(shù)據(jù)的收發(fā)
c.關(guān)閉鏈接

package main
 
import (
    "bufio"
    "fmt"
    "net"
    "os"
    "strings"
)
 
func main() {
    //1.建立一個鏈接（Dial撥號）
    conn, err := net.Dial("tcp", "0.0.0.0:20000")
    if err != nil {
        fmt.Printf("dial failed, err:%v\n", err)
        return
    }
 
    fmt.Println("Conn Established...:")
 
    //讀入輸入的信息
    reader := bufio.NewReader(os.Stdin)
    for {
        data, err := reader.ReadString('\n')
        if err != nil {
            fmt.Printf("read from console failed, err:%v\n", err)
            break
        }
 
        data = strings.TrimSpace(data)
        //傳輸數(shù)據(jù)到服務(wù)端
        _, err = conn.Write([]byte(data))
        if err != nil {
            fmt.Printf("write failed, err:%v\n", err)
            break
        }
    }
}

執(zhí)??下:

客戶端:

服務(wù)端：

?、使用Golang創(chuàng)建?個HTTP連接

A.HTTP協(xié)議是基于TCP協(xié)議之上的?本協(xié)議。
B.每行?本使?\r\n結(jié)尾，當(dāng)連續(xù)兩個\r\n時，表示整個數(shù)據(jù)包結(jié)束。

package main
 
import (
    "fmt"
    "io"
    "net"
)
 
func main() {
    conn, err := net.Dial("tcp", "www.baidu.com:80")
    if err != nil {
        fmt.Printf("dial failed, err:%v\n", err)
        return
    }
 
    data := "GET / HTTP/1.1\r\n"
    data += "HOST: www.baidu.com\r\n"
    data += "connection: close\r\n"
    data += "\r\n\r\n"
 
    //寫入數(shù)據(jù)
    _, err = io.WriteString(conn, data)
    if err != nil {
        fmt.Printf("wirte string failed, err:%v\n", err)
        return
    }
 
    var buf [1024]byte
    for {
        //讀取返回的數(shù)據(jù)
        n, err := conn.Read(buf[:])
        if err != nil || n == 0 {
            break
        }
 
        fmt.Println(string(buf[:n]))
    }
}

三、使?用Golang創(chuàng)建?個UDP連接

1.服務(wù)流程，相比于TCP連接需要Accept一個鏈接，UDP不需要進?這步操作，服務(wù)端代碼如下:

package main
 
import (
    "fmt"
    "net"
)
 
func main() {
    //建立一個UDP的監(jiān)聽，這里使用的是ListenUDP，并且地址是一個結(jié)構(gòu)體
    listen, err := net.ListenUDP("udp", &net.UDPAddr{
        IP:   net.IPv4(0, 0, 0, 0),
        Port: 8080,
    })
    if err != nil {
        fmt.Printf("listen failed, err:%v\n", err)
        return
    }
 
    for {
        var data [1024]byte
        //讀取UDP數(shù)據(jù)
        count, addr, err := listen.ReadFromUDP(data[:])
        if err != nil {
            fmt.Printf("read udp failed, err:%v\n", err)
            continue
        }
 
        fmt.Printf("data:%s addr:%v count:%d\n", string(data[0:count]), addr, count)
        //返回數(shù)據(jù)
        _, err = listen.WriteToUDP([]byte("hello client"), addr)
        if err != nil {
            fmt.Printf("write udp failed, err:%v\n", err)
            continue
        }
    }
}

2.客戶端流程

package main
 
import (
    "fmt"
    "net"
)
 
func main() {
    // 創(chuàng)建連接
    socket, err := net.DialUDP("udp4", nil, &net.UDPAddr{
        IP:   net.IPv4(127, 0, 0, 1),
        Port: 8080,
    })
    if err != nil {
        fmt.Println("連接失敗!", err)
        return
    }
    defer socket.Close()
    // 發(fā)送數(shù)據(jù)
    senddata := []byte("hello server!")
    _, err = socket.Write(senddata)
    if err != nil {
        fmt.Println("發(fā)送數(shù)據(jù)失敗!", err)
        return
    }
    // 接收數(shù)據(jù)
    data := make([]byte, 4096)
    read, remoteAddr, err := socket.ReadFromUDP(data)
    if err != nil {
        fmt.Println("讀取數(shù)據(jù)失敗!", err)
        return
    }
    fmt.Println(read, remoteAddr)
    fmt.Printf("%s\n", data)
}