[网络协议]15 网络编程

TCP协议

TCP服务端编程：

package main

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

func clientor(c net.Conn) {
	clientAddr := c.RemoteAddr().String()

	for {
		//1.接收客户端消息
		buf := make([]byte, 128)
		_, err := c.Read(buf)
		if err != nil {
			fmt.Println("conneter read error.", err)
			break
		}

		fmt.Printf("[%v]:%v\n", clientAddr, string(buf))

		//2.给客户端回复
		c.Write([]byte("收到！"))
	}
}

func main() {
	listener, err := net.Listen("tcp", "127.0.0.1:8888")
	if err != nil {
		fmt.Println("tcp listen error.", err)
		os.Exit(1)
	}

	for {
		conneter, err := listener.Accept()
		if err != nil {
			fmt.Println("listener accept error.", err)
			os.Exit(2)
		}

		go clientor(conneter)
	}
}

TCP客户端编程：

package main

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

var wg sync.WaitGroup

func server(c net.Conn) {
	defer wg.Done()

	serverAddr := c.RemoteAddr().String()
	reader := bufio.NewReader(os.Stdin)

	for {
		//1.从终端读取用户输入
		fmt.Print("# ")
		msg, _ := reader.ReadString('\n') //读到换行符
		msg = strings.TrimSpace(msg)      //删除前后空格

		//2.向服务端发送消息
		c.Write([]byte(msg))

		//3.接收服务端回复
		buf := make([]byte, 128)
		_, err := c.Read(buf)
		if err != nil {
			fmt.Println("conneter read error.", err)
		}

		fmt.Printf("[%v]:%v\n", serverAddr, string(buf))
	}
}

func main() {
	//1.连接服务端
	conn, err := net.Dial("tcp", "127.0.0.1:8888")
	if err != nil {
		fmt.Println("tcp Dial error.", err)
		os.Exit(1)
	}

	wg.Add(1)
	go server(conn)

	wg.Wait()
}

UDP协议

UDP服务端编程：

package main

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

func checkErr(err error) {
	if err != nil {
		fmt.Println("ERROR:", err)
		os.Exit(1)
	}
}

func main() {
	//1.启动一个UDP监听
	udpSocket, err := net.ListenUDP("udp", &net.UDPAddr{
		IP:   net.IPv4(127, 0, 0, 1),
		Port: 8888,
	})

	checkErr(err)
	defer udpSocket.Close()
	fmt.Println("UDP服务已启动...")

	for {
		//UDP读数据
		readbuf := make([]byte, 128)
		_, rAddr, err := udpSocket.ReadFromUDP(readbuf)
		checkErr(err)
		fmt.Printf("[%v]:%s\n", rAddr.String(), readbuf)

		//UDP写数据
		writebuf := []byte(strings.ToUpper(string(readbuf)))
		_, err = udpSocket.WriteToUDP(writebuf, rAddr)
		checkErr(err)
	}
}

UDP客户端编程：

package main

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

func checkErr(err error) {
	if err != nil {
		fmt.Println("ERROR:", err)
		os.Exit(1)
	}
}

func main() {
	socket, err := net.DialUDP("udp", nil, &net.UDPAddr{
		IP:   net.IPv4(127, 0, 0, 1),
		Port: 8888,
	})

	checkErr(err)
	defer socket.Close()

	reader := bufio.NewReader(os.Stdin)
	for {
		//从终端读取用户输入
		fmt.Print("请输入：")
		msg, _ := reader.ReadString('\n') //读到换行符
		msg = strings.TrimSpace(msg)      //删除前后空格

		//从UDP发送数据
		_, err = socket.Write([]byte(msg))
		checkErr(err)

		//从UDP接收数据
		buf := make([]byte, 128)
		_, rAddr, err := socket.ReadFromUDP(buf)
		checkErr(err)
		fmt.Printf("[%v]:%s\n", rAddr.String(), buf)
	}
}

HTTP协议

HTTP服务端编程：

package main

import (
	"io/ioutil"
	"net/http"
)

/*
xx.txt
<h1 style="color:red"> Hello GO!<h1>
<a href="https://www.baidu.com">跳转到百度</a>
*/
func TestShow(response http.ResponseWriter, request *http.Request) {
	ret, err := ioutil.ReadFile("./xx.txt")
	if err != nil {
		response.Write([]byte(err.Error()))
	}

	response.Write([]byte(ret))
}

func main() {
	//链接：http://127.0.0.1:8080/TestShow
	http.HandleFunc("/TestShow", TestShow)
	http.ListenAndServe("127.0.0.1:8080", nil)
}

HTTP客户端编程：

//方法1
package main

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"os"
)

func checkErr(err error) {
	if err != nil {
		fmt.Println("ERROR:", err)
		os.Exit(1)
	}
}

func main() {
	resp, err := http.Get("https://www.baidu.com")
	checkErr(err)

	buf, err := ioutil.ReadAll(resp.Body)
	checkErr(err)

	fmt.Println(string(buf))
}

//方法2
package main

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"
	"os"
)

func checkErr(err error) {
	if err != nil {
		fmt.Println("ERROR:", err)
		os.Exit(1)
	}
}

func main() {
	data := url.Values{}
	data.Set("name", "张三")
	data.Set("age", "100")
	queryStr := data.Encode()

	fmt.Println(queryStr) //age=100&name=%E5%BC%A0%E4%B8%89

	urlObj, _ := url.Parse("https://www.baidu.com")
	urlObj.RawQuery = queryStr
	req, err := http.NewRequest("GET", urlObj.String(), nil)
	checkErr(err)

	fmt.Println(req.URL.String()) //https://www.baidu.com?age=100&name=%E5%BC%A0%E4%B8%89

	resp, err := http.DefaultClient.Do(req)
	checkErr(err)

	buf, err := ioutil.ReadAll(resp.Body)
	checkErr(err)

	fmt.Println(string(buf))

	defer resp.Body.Close()
}