Go練習題（11）

net包練習

//server.go
package main

import (
	"bufio"
	"fmt"
	"io/ioutil"
	"net"
	"os"
	"path/filepath"
	"strings"
)
//這裏的獨寫用的是小文件  如果文件較大適合用bufio 或者read 分批次字節切片讀取
var (
	binPath string
	dirPath string
	defaultFileName string
	file404 string
	file500 string
)

func Header(conn net.Conn) {
	defer func() {
		conn.Close()
		fmt.Println("client closed",conn.RemoteAddr())
	}()
	fmt.Println("Client Connected:",conn.RemoteAddr())
	//處理客戶端數據
	reader := bufio.NewReader(conn)
	//讀取數據
	line,err := reader.ReadString('\n')
	if err != nil {
		fmt.Println(err)
	}else {
		//正常處理
		nodes := strings.Fields(line)
		//獲取請求資源(本地)路徑
		path := filepath.Join(dirPath,nodes[1])
		//如果請求路徑報錯的話 判斷
		if info,err := os.Stat(path);err != nil {
			//不存在 返回404的路徑
			if os.IsNotExist(err){
				path = file404
				//不是因爲不存在報錯返回500
			}else {
				path = file500
			}
		}else {
			//判斷請求路徑存在的話是目錄還是文件
			//是目錄默認返回index.html
			if info.IsDir(){
				path = filepath.Join(path,defaultFileName)
			}
			////是文件就直接返回
		}
		//再次對path進行檢查(404.html/500.html/index.html)
		if _,err := os.Stat(path);err == nil {
			//fprint 寫入文件
			fmt.Fprint(conn,"HTTP/1.1 %v 200 OK\r\n")
			fmt.Fprint(conn,"Server:aaserver \r\n")
			fmt.Fprint(conn,"\r\n")
			bytes,_ := ioutil.ReadFile(path)
			conn.Write(bytes)
		}else {
			fmt.Println(err)
		}
	}
}

func main() {
	//獲取當前運行文件的路徑
	binPath,_ = filepath.Abs(os.Args[0])
	//獲取父目錄
	dirPath  = filepath.Dir(binPath)
	//默認路徑
	defaultFileName  = "index.html"
	//錯誤路徑
	file404  = filepath.Join(dirPath,"404.html")
	file500  = filepath.Join(dirPath,"500.html")
	addr := ":9999"
	//監聽端口
	listener,err := net.Listen("tcp",addr)
	if err != nil {
		fmt.Println(err)
		os.Exit(-1)
	}
	//延遲關閉
	defer listener.Close()
	fmt.Println("Listen on",listener.Addr())
	for {
		//獲取請求
		conn,err := listener.Accept()
		if err != nil {
			fmt.Println(err)
			continue
		}
		//用例程可以實現多併發處理請求
		go Header(conn)
	}
}

//client.go
package main

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

func main() {
	addr := "127.0.0.1:9999"
	url := "/once.go"
	client,err := net.Dial("tcp",addr)
	if err != nil {
		fmt.Println(err)
		os.Exit(-1)
	}
	fmt.Fprintf(client,"Get %s HTTP/1.0\r\n",url)

	reader := bufio.NewReader(client)
	line,err := reader.ReadString('\n')
	fmt.Println("請求行:")
	fmt.Println("\t",line)
	fmt.Println("請求頭:")
	for {
		line,err := reader.ReadString('\n')
		if err != nil {
			if err != io.EOF{
				fmt.Println(err)
			}
			break
		}
		if line == "\r\n" {
			break
		}
		//因爲line就自帶換行所以用print打印
		fmt.Print("\t",line)
	}
	fmt.Println("響應體:")
	for {
		line, err := reader.ReadString('\n')
		if err != nil {
			if err != io.EOF {
				fmt.Println(err)
			}
			break
		}
		if line == "\r\n" {
			break
		}

		//因爲line就自帶換行所以用print打印
		fmt.Print("\t", line)
	}
	client.Close()
}