在上篇博客中寫到如何用Python實現一個類似tomcat的簡單服務器，接下來用go語言去實現

1. Go本身自己封裝實現了非常簡單的httpServer

package main

import (
    "bufio"
    "fmt"
    "io"
    "net/http"
    "os"
    "strings"
)

func main() {
    //http請求處理
    http.HandleFunc("/", handler1)
    //綁定監聽地址和端口
    http.ListenAndServe("localhost:8080", nil)
}

//請求處理函數
func handler1(w http.ResponseWriter, r *http.Request) {
    //獲取請求資源
    path := r.URL.Path
    if strings.Contains(path[1:], "") {
        //返回請求資源
        fmt.Fprintf(w, getHtmlFile("index.html"))
    } else {
        if strings.Contains(path[1:], ".html") {
            w.Header().Set("content-type", "text/html")
            fmt.Fprintf(w, getHtmlFile(path[1:]))
        }
        if strings.Contains(path[1:], ".css") {
            w.Header().Set("content-type", "text/css")
            fmt.Fprintf(w, getHtmlFile(path[1:]))
        }
        if strings.Contains(path[1:], ".js") {
            w.Header().Set("content-type", "text/javascript")
            fmt.Fprintf(w, getHtmlFile(path[1:]))
        }
        if strings.Contains(path[1:], "") {
            fmt.Print(strings.Contains(path[1:], ""))
        }
    }

}

func getHtmlFile(path string) (fileHtml string) {
    file, err := os.Open(path)
    if err != nil {
        panic(err)
    }
    defer file.Close()

    rd := bufio.NewReader(file)
    for {
        line, err := rd.ReadString('\n')

        if err != nil || io.EOF == err {
            break
        }
        fileHtml += line
    }
    return fileHtml
}

從上面的代碼可以看出，關鍵的依賴是net/http，這個類庫實現得非常好，而且支持并發，在這個就不去分析源碼。

2. 但對于自己實現簡易的服務器，最好還是用socket去實現：

實現之前還是需具備了解http等一些基礎知識，因為上篇博客已經介紹了，所以在這里不介紹了 直接寫代碼

package main

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

func main() {
    //確定協議及綁定IP及端口
    netListen, err := net.Listen("tcp", "localhost:8080")
    CheckError(err)
    defer netListen.Close()
    Log("waiting for client request")
    for {
        //接受請求連接
        conn, err := netListen.Accept()
        if err != nil {
            CheckError(err)
            break
        } else {
            Log(conn.RemoteAddr().String(), "tcp connect success")
            //處理請求連接
            handleConnection(conn)
        }
        conn.Close()
    }
}

//處理請求連接函數
func handleConnection(conn net.Conn) {
    buffer := make([]byte, 2048)
    n, err := conn.Read(buffer)
    if err != nil {
        Log(conn.RemoteAddr().String(), " connection error: ", err)
        conn.Close()
    } else {
        Log(conn.RemoteAddr().String(), "receive data string:\n", string(buffer[:n]))
        //返回數據給客戶端
        responseInfoToClient(conn, string(buffer[:n]), err)
    }
}

//返回數據的函數
func responseInfoToClient(conn net.Conn, requestInfo string, err error) {
    //獲取http協議頭
    conn.Write([]byte(getFileContent("head.md")))
    conn.Write([]byte("\n"))
    var path string = strings.Replace(getMidStr(requestInfo, "GET /", "HTTP"), " ", "", -1)
    fmt.Println(path)
    if path != "" {
        if path == "favicon.ico" {
            fmt.Println("every connect hava favicon.ico resource request")
        } else {
            _, err = os.Open(path)
            if err != nil {
                fmt.Println("RESTful")
            } else {
                conn.Write([]byte(getFileContent(path)))
            }
        }
    } else {
        conn.Write([]byte(getFileContent("index.html")))
    }
}

func getMidStr(data string, startStr string, endStr string) (reqSouce string) {
    var startIndex int = strings.Index(data, startStr)
    var info string
    if startIndex >= 0 {
        startIndex += len(startStr)
        var endIndex int = strings.Index(data, endStr)
        info = data[startIndex:endIndex]
    }
    return info
}

func getFileContent(path string) (fileInfo string) {
    file, err := os.Open(path)
    if err != nil {
        panic(err)
    }
    defer file.Close()

    rd := bufio.NewReader(file)
    for {
        line, err := rd.ReadString('\n')

        if err != nil || io.EOF == err {
            break
        }
        fileInfo += line
    }
    return fileInfo
}

func Log(v ...interface{}) {
    log.Println(v...)
}

func CheckError(err error) {
    if err != nil {
        fmt.Fprintf(os.Stderr, "Fatal error: %s", err.Error())
        os.Exit(1)
    }
}

源碼下載：https://github.com/Jiashengp/GoHttpServer