golang设置http response响应头与填坑记录

w.WriteHeader(201)
w.Header().Set("Name", "my name is smallsoup")

w.WriteHeader(404)

func (w *response) WriteHeader(code int) {
 if w.conn.hijacked() {
 w.conn.server.logf("http: response.WriteHeader on hijacked connection")
 return
 }
//第二次WriteHeader()进来满足if条件就报错直接return
 if w.wroteHeader {
 w.conn.server.logf("http: multiple response.WriteHeader calls")
 return
 }
//第一次write()进来这里会将w.wroteHeader置为true
 w.wroteHeader = true
 w.status = code

 if w.calledHeader && w.cw.header == nil {
 w.cw.header = w.handlerHeader.clone()
 }

 if cl := w.handlerHeader.get("Content-Length"); cl != "" {
 v, err := strconv.ParseInt(cl, 10, 64)
 if err == nil && v >= 0 {
 w.contentLength = v
 } else {
 w.conn.server.logf("http: invalid Content-Length of %q", cl)
 w.handlerHeader.Del("Content-Length")
 }
 }
}

for i, c := range a {
 // 规范化:首字母大写
 // - 之后单子的首字母大写
 // 如:(Host, User-Agent, If-Modified-Since).
 if upper && 'a' <= c && c <= 'z' {
 //大写转小写
 c -= toLower
 } else if !upper && 'A' <= c && c <= 'Z' {
 //小写转大写
 c += toLower
 }
 //重新给key数组赋值
 a[i] = c
 //设置大小写标志位
 upper = c == '-' // for next time
}

package main

import (
 "net/http"
)

func main() {

 http.HandleFunc("/", func (w http.ResponseWriter, r *http.Request){


 w.Header().Set("name", "my name is smallsoup")
 w.WriteHeader(500)
 w.Write([]byte("hello world\n"))

 })

 http.ListenAndServe(":8080", nil)
}

package main

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

func main() {

 myHttpGet()

}

func myHttpGet() {

 rsp, err := http.Get("http://localhost:8080")
 if err != nil {
 fmt.Println("myHttpGet error is ", err)
 return
 }

 defer rsp.Body.Close()
 body, err := ioutil.ReadAll(rsp.Body)
 if err != nil {
 fmt.Println("myHttpGet error is ", err)
 return
 }

 fmt.Println("response statuscode is ", rsp.StatusCode, 
 "\nhead[name]=", rsp.Header["Name"], 
 "\nbody is ", string(body))
}

go run myServer.go

go run myHttp.go

response, err = ioutil.ReadAll(resp.Body)
if err != nil {
log.Println("ioutil ReadAll failed :", err.Error())
return
}

type ReadCloser interface {
Reader
Closer
}

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

byte1,err := ioutil.ReadAll(fi)
fmt.Println(string(byte1))

byte2,err := ioutil.ReadAll(fi)
fmt.Println(string(byte2))

return string(fd)
}

fi2:= ioutil.NopCloser(bytes.NewBuffer(byte1))
byte3,err := ioutil.ReadAll(fi2)
fmt.Println(string(byte3))