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import "net/http"
概述
索引
示例
子目录
概述
http包提供HTTP客户端和服务器实现。
Get，Head，Post和PostForm发出HTTP（或HTTPS）请求：
resp, err := http.Get("http://example.com/")...resp, err := http.Post("http://example.com/upload", "image/jpeg", &buf)...resp, err := http.PostForm("http://example.com/form",
url.Values{"key": {"Value"}, "id": {"123"}})客户必须在完成后关闭响应主体：
resp, err := http.Get("http://example.com/")if err != nil {// handle error}defer resp.Body.Close()body, err := ioutil.ReadAll(resp.Body)// ...要控制HTTP客户端标题，重定向策略和其他设置，请创建一个客户端：
client := &http.Client{
CheckRedirect: redirectPolicyFunc,}resp, err := client.Get("http://example.com")// ...req, err := http.NewRequest("GET", "http://example.com", nil)// ...req.Header.Add("If-None-Match", `W/"wyzzy"`)resp, err := client.Do(req)// ...为了控制代理，TLS配置，保活，压缩和其他设置，请创建一个传输：
tr := &http.Transport{
MaxIdleConns: 10,
IdleConnTimeout: 30 * time.Second,
DisableCompression: true,}client := &http.Client{Transport: tr}resp, err := client.Get("https://example.com")客户端和传输对于多个goroutine并发使用是安全的，并且效率应该只创建一次并重新使用。
ListenAndServe启动一个具有给定地址和处理程序的HTTP服务器。处理程序通常为零，这意味着使用DefaultServeMux。Handle和HandleFunc将处理程序添加到DefaultServeMux：
http.Handle("/foo", fooHandler)http.HandleFunc("/bar", func(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path))})log.Fatal(http.ListenAndServe(":8080", nil))通过创建自定义服务器，可以更好地控制服务器的行为：
s := &http.Server{
Addr: ":8080",
Handler: myHandler,
ReadTimeout: 10 * time.Second,
WriteTimeout: 10 * time.Second,
MaxHeaderBytes: 1 << 20,}log.Fatal(s.ListenAndServe())从Go 1.6开始，http包在使用HTTPS时对HTTP/2协议有透明的支持。必须禁用HTTP/2的程序可以通过将Transport.TLSNextProto（对于客户端）或Server.TLSNextProto（对于服务器）设置为非零空映射来实现。或者，当前支持以下GODEBUG环境变量：
GODEBUG=http2client=0 # disable HTTP/2 client support GODEBUG=http2server=0 # disable HTTP/2 server support GODEBUG=http2debug=1 # enable verbose HTTP/2 debug logs GODEBUG=http2debug=2 # ... even more verbose, with frame dumps
Go的API兼容性承诺不涵盖GODEBUG变量。
http包的传输和服务器都自动为简单配置启用HTTP/2支持。要为更复杂的配置启用HTTP/2，使用较低级别的HTTP/2功能或使用Go的http2软件包的较新版本，请直接导入“golang.org/x/net/http2”并使用其配置传输和/或ConfigureServer功能。通过golang.org/x/net/http2软件包手动配置HTTP/2优先于net/http软件包内置的HTTP/2支持。
索引
常量
变量
func CanonicalHeaderKey(s string) string
func DetectContentType(data []byte) string
func Error(w ResponseWriter, error string, code int)
func Handle(pattern string, handler Handler)
func HandleFunc(pattern string, handler func(ResponseWriter, *Request))
func ListenAndServe(addr string, handler Handler) error
func ListenAndServeTLS(addr, certFile, keyFile string, handler Handler) error
func MaxBytesReader(w ResponseWriter, r io.ReadCloser, n int64) io.ReadCloser
func NotFound(w ResponseWriter, r *Request)
func ParseHTTPVersion(vers string) (major, minor int, ok bool)
func ParseTime(text string) (t time.Time, err error)
func ProxyFromEnvironment(req *Request) (*url.URL, error)
func ProxyURL(fixedURL *url.URL) func(*Request) (*url.URL, error)
func Redirect(w ResponseWriter, r *Request, url string, code int)
func Serve(l net.Listener, handler Handler) error
func ServeContent(w ResponseWriter, req *Request, name string, modtime time.Time, content io.ReadSeeker)
func ServeFile(w ResponseWriter, r *Request, name string)
func ServeTLS(l net.Listener, handler Handler, certFile, keyFile string) error
func SetCookie(w ResponseWriter, cookie *Cookie)
func StatusText(code int) string
type Client
func (c *Client) Do(req *Request) (*Response, error)
func (c *Client) Get(url string) (resp *Response, err error)
func (c *Client) Head(url string) (resp *Response, err error)
func (c *Client) Post(url string, contentType string, body io.Reader) (resp *Response, err error)
func (c *Client) PostForm(url string, data url.Values) (resp *Response, err error)
type CloseNotifier
type ConnState
func (c ConnState) String() string
type Cookie
func (c *Cookie) String() string
type CookieJar
type Dir
func (d Dir) Open(name string) (File, error)
type File
type FileSystem
type Flusher
type Handler
func FileServer(root FileSystem) Handler
func NotFoundHandler() Handler
func RedirectHandler(url string, code int) Handler
func StripPrefix(prefix string, h Handler) Handler
func TimeoutHandler(h Handler, dt time.Duration, msg string) Handler
type HandlerFunc
func (f HandlerFunc) ServeHTTP(w ResponseWriter, r *Request)
type Header
func (h Header) Add(key, value string)
func (h Header) Del(key string)
func (h Header) Get(key string) string
func (h Header) Set(key, value string)
func (h Header) Write(w io.Writer) error
func (h Header) WriteSubset(w io.Writer, exclude map[string]bool) error
type Hijacker
type ProtocolError
func (pe *ProtocolError) Error() string
type PushOptions
type Pusher
type Request
func NewRequest(method, url string, body io.Reader) (*Request, error)
func ReadRequest(b *bufio.Reader) (*Request, error)
func (r *Request) AddCookie(c *Cookie)
func (r *Request) BasicAuth() (username, password string, ok bool)
func (r *Request) Context() context.Context
func (r *Request) Cookie(name string) (*Cookie, error)
func (r *Request) Cookies() []*Cookie
func (r *Request) FormFile(key string) (multipart.File, *multipart.FileHeader, error)
func (r *Request) FormValue(key string) string
func (r *Request) MultipartReader() (*multipart.Reader, error)
func (r *Request) ParseForm() error
func (r *Request) ParseMultipartForm(maxMemory int64) error
func (r *Request) PostFormValue(key string) string
func (r *Request) ProtoAtLeast(major, minor int) bool
func (r *Request) Referer() string
func (r *Request) SetBasicAuth(username, password string)
func (r *Request) UserAgent() string
func (r *Request) WithContext(ctx context.Context) *Request
func (r *Request) Write(w io.Writer) error
func (r *Request) WriteProxy(w io.Writer) error
type Response
func Get(url string) (resp *Response, err error)
func Head(url string) (resp *Response, err error)
func Post(url string, contentType string, body io.Reader) (resp *Response, err error)
func PostForm(url string, data url.Values) (resp *Response, err error)
func ReadResponse(r *bufio.Reader, req *Request) (*Response, error)
func (r *Response) Cookies() []*Cookie
func (r *Response) Location() (*url.URL, error)
func (r *Response) ProtoAtLeast(major, minor int) bool
func (r *Response) Write(w io.Writer) error
type ResponseWriter
type RoundTripper
func NewFileTransport(fs FileSystem) RoundTripper
type ServeMux
func NewServeMux() *ServeMux
func (mux *ServeMux) Handle(pattern string, handler Handler)
func (mux *ServeMux) HandleFunc(pattern string, handler func(ResponseWriter, *Request))
func (mux *ServeMux) Handler(r *Request) (h Handler, pattern string)
func (mux *ServeMux) ServeHTTP(w ResponseWriter, r *Request)
type Server
func (srv *Server) Close() error
func (srv *Server) ListenAndServe() error
func (srv *Server) ListenAndServeTLS(certFile, keyFile string) error
func (srv *Server) RegisterOnShutdown(f func())
func (srv *Server) Serve(l net.Listener) error
func (srv *Server) ServeTLS(l net.Listener, certFile, keyFile string) error
func (srv *Server) SetKeepAlivesEnabled(v bool)
func (srv *Server) Shutdown(ctx context.Context) error
type Transport
func (t *Transport) CancelRequest(req *Request)
func (t *Transport) CloseIdleConnections()
func (t *Transport) RegisterProtocol(scheme string, rt RoundTripper)
func (t *Transport) RoundTrip(req *Request) (*Response, error)
示例
FileServer FileServer (StripPrefix) Get Hijacker ResponseWriter (Trailers) ServeMux.Handle StripPrefix
文件包
client.go cookie.go doc.go filetransport.go fs.go h2_bundle.go header.go http.go jar.go method.go request.go response.go server.go sniff.go status.go transfer.go transport.go
常量
常见的HTTP方法。
除非另有说明，否则这些在RFC 7231第4.3节中定义。
const ( MethodGet = "GET" MethodHead = "HEAD" MethodPost = "POST" MethodPut = "PUT" MethodPatch = "PATCH" // RFC 5789 MethodDelete = "DELETE" MethodConnect = "CONNECT" MethodOptions = "OPTIONS" MethodTrace = "TRACE")
向IANA注册的HTTP状态代码。
const ( StatusContinue = 100 // RFC 7231, 6.2.1 StatusSwitchingProtocols = 101 // RFC 7231, 6.2.2 StatusProcessing = 102 // RFC 2518, 10.1 StatusOK = 200 // RFC 7231, 6.3.1 StatusCreated = 201 // RFC 7231, 6.3.2 StatusAccepted = 202 // RFC 7231, 6.3.3 StatusNonAuthoritativeInfo = 203 // RFC 7231, 6.3.4 StatusNoContent = 204 // RFC 7231, 6.3.5 StatusResetContent = 205 // RFC 7231, 6.3.6 StatusPartialContent = 206 // RFC 7233, 4.1 StatusMultiStatus = 207 // RFC 4918, 11.1 StatusAlreadyReported = 208 // RFC 5842, 7.1 StatusIMUsed = 226 // RFC 3229, 10.4.1 StatusMultipleChoices = 300 // RFC 7231, 6.4.1 StatusMovedPermanently = 301 // RFC 7231, 6.4.2 StatusFound = 302 // RFC 7231, 6.4.3 StatusSeeOther = 303 // RFC 7231, 6.4.4 StatusNotModified = 304 // RFC 7232, 4.1 StatusUseProxy = 305 // RFC 7231, 6.4.5 StatusTemporaryRedirect = 307 // RFC 7231, 6.4.7 StatusPermanentRedirect = 308 // RFC 7538, 3 StatusBadRequest = 400 // RFC 7231, 6.5.1 StatusUnauthorized = 401 // RFC 7235, 3.1 StatusPaymentRequired = 402 // RFC 7231, 6.5.2 StatusForbidden = 403 // RFC 7231, 6.5.3 StatusNotFound = 404 // RFC 7231, 6.5.4 StatusMethodNotAllowed = 405 // RFC 7231, 6.5.5 StatusNotAcceptable = 406 // RFC 7231, 6.5.6 StatusProxyAuthRequired = 407 // RFC 7235, 3.2 StatusRequestTimeout = 408 // RFC 7231, 6.5.7 StatusConflict = 409 // RFC 7231, 6.5.8 StatusGone = 410 // RFC 7231, 6.5.9 StatusLengthRequired = 411 // RFC 7231, 6.5.10 StatusPreconditionFailed = 412 // RFC 7232, 4.2 StatusRequestEntityTooLarge = 413 // RFC 7231, 6.5.11 StatusRequestURITooLong = 414 // RFC 7231, 6.5.12 StatusUnsupportedMediaType = 415 // RFC 7231, 6.5.13 StatusRequestedRangeNotSatisfiable = 416 // RFC 7233, 4.4 StatusExpectationFailed = 417 // RFC 7231, 6.5.14 StatusTeapot = 418 // RFC 7168, 2.3.3 StatusUnprocessableEntity = 422 // RFC 4918, 11.2 StatusLocked = 423 // RFC 4918, 11.3 StatusFailedDependency = 424 // RFC 4918, 11.4 StatusUpgradeRequired = 426 // RFC 7231, 6.5.15 StatusPreconditionRequired = 428 // RFC 6585, 3 StatusTooManyRequests = 429 // RFC 6585, 4 StatusRequestHeaderFieldsTooLarge = 431 // RFC 6585, 5 StatusUnavailableForLegalReasons = 451 // RFC 7725, 3 StatusInternalServerError = 500 // RFC 7231, 6.6.1 StatusNotImplemented = 501 // RFC 7231, 6.6.2 StatusBadGateway = 502 // RFC 7231, 6.6.3 StatusServiceUnavailable = 503 // RFC 7231, 6.6.4 StatusGatewayTimeout = 504 // RFC 7231, 6.6.5 StatusHTTPVersionNotSupported = 505 // RFC 7231, 6.6.6 StatusVariantAlsoNegotiates = 506 // RFC 2295, 8.1 StatusInsufficientStorage = 507 // RFC 4918, 11.5 StatusLoopDetected = 508 // RFC 5842, 7.2 StatusNotExtended = 510 // RFC 2774, 7 StatusNetworkAuthenticationRequired = 511 // RFC 6585, 6)
DefaultMaxHeaderBytes是HTTP请求中头部允许的最大大小。这可以通过设置Server.MaxHeaderBytes来覆盖。
const DefaultMaxHeaderBytes = 1 << 20 // 1 MB
DefaultMaxIdleConnsPerHost是Transport的MaxIdleConnsPerHost的默认值。
const DefaultMaxIdleConnsPerHost = 2
TimeFormat是在HTTP头中生成时间时使用的时间格式。它就像time.RFC1123一样，但是将GMT编码为时区。格式化的时间必须以UTC格式生成正确的格式。
有关解析此时间格式的信息，请参阅ParseTime。
const TimeFormat = "Mon, 02 Jan 2006 15:04:05 GMT"
TrailerPrefix是ResponseWriter.Header映射键的奇幻的前缀，如果存在，它表示映射条目实际上是用于响应预告片的，而不是响应标头。在ServeHTTP呼叫结束并且值在trailers中发送后，该前缀被剥离。
该机制仅适用于在写入标题之前未知的trailers。如果在写入标题之前，一套trailers是固定的或已知的，则优选正常的trailers机制：
https://golang.org/pkg/net/http/#ResponseWriter https://golang.org/pkg/net/http/#example_ResponseWriter_trailers
const TrailerPrefix = "Trailer:"
变量
var ( // 推送法返回 ErrNotSupported // 实现来指示 HTTP\/2 推送支持不是 // 可用。
ErrNotSupported = &ProtocolError{"feature not supported"} // ErrUnexpectedTrailer 由传输返回, 当服务器 // 答复与拖车头, 但没有块答复。
ErrUnexpectedTrailer = &ProtocolError{"trailer header without chunked transfer encoding"} // ErrMissingBoundary 是按请求返回的. MultipartReader 当 // request's Content-Type does not include a "boundary" parameter.
ErrMissingBoundary = &ProtocolError{"no multipart boundary param in Content-Type"} // ErrNotMultipart is returned by Request.MultipartReader when the // request's Content-Type is not multipart/form-data.
ErrNotMultipart = &ProtocolError{"request Content-Type isn't multipart/form-data"} // Deprecated: ErrHeaderTooLong is not used.
ErrHeaderTooLong = &ProtocolError{"header too long"} // Deprecated: ErrShortBody is not used.
ErrShortBody = &ProtocolError{"entity body too short"} // Deprecated: ErrMissingContentLength is not used.
ErrMissingContentLength = &ProtocolError{"missing ContentLength in HEAD response"})HTTP服务器使用的错误。
var ( // ErrBodyNotAllowed is returned by ResponseWriter.Write calls // when the HTTP method or response code does not permit a // body.
ErrBodyNotAllowed = errors.New("http: request method or response status code does not allow body") // ErrHijacked is returned by ResponseWriter.Write calls when // the underlying connection has been hijacked using the // Hijacker interface. A zero-byte write on a hijacked // connection will return ErrHijacked without any other side // effects.
ErrHijacked = errors.New("http: connection has been hijacked") // ErrContentLength is returned by ResponseWriter.Write calls // when a Handler set a Content-Length response header with a // declared size and then attempted to write more bytes than // declared.
ErrContentLength = errors.New("http: wrote more than the declared Content-Length") // Deprecated: ErrWriteAfterFlush is no longer used.
ErrWriteAfterFlush = errors.New("unused"))var ( // ServerContextKey 是一个上下文键。可用于 HTTP // 具有上下文的处理程序。WithValue 访问服务器, // 已启动处理程序。关联的值将为 // 类型 * 服务器。
ServerContextKey = &contextKey{"http-server"} // LocalAddrContextKey 是一个上下文键。可用于 // 带有上下文的 HTTP 处理程序。WithValue 访问地址 // 连接到达的本地地址。 // 关联的值将为类型网。地址.
LocalAddrContextKey = &contextKey{"local-addr"})DefaultClient是默认的客户端，由Get，Head和Post使用。
var DefaultClient = &Client{}DefaultServeMux是Serve使用的默认ServeMux。
var DefaultServeMux = &defaultServeMux
ErrAbortHandler是中止处理程序的标志性恐慌值。虽然ServeHTTP的任何恐慌都会中止对客户端的响应，但使用ErrAbortHandler进行恐慌也会禁止将堆栈跟踪记录到服务器的错误日志中。
var ErrAbortHandler = errors.New("net/http: abort Handler")在正文关闭后读取Request或Response Body时返回ErrBodyReadAfterClose。这通常发生在HTTP处理程序在其ResponseWriter上调用WriteHeader或Write之后读取主体时。
var ErrBodyReadAfterClose = errors.New("http: invalid Read on closed Body")在超时的处理程序中的ResponseWriter Write调用上返回ErrHandlerTimeout。
var ErrHandlerTimeout = errors.New("http: Handler timeout")当读取格式不正确的分块编码的请求或响应主体时，返回ErrLineTooLong。
var ErrLineTooLong = internal.ErrLineTooLong
当提供的文件字段名称不存在于请求中或文件字段中时，FormFile将返回ErrMissingFile。
var ErrMissingFile = errors.New("http: no such file")当找不到cookie时，ErrNoCookie通过Request的Cookie方法返回。
var ErrNoCookie = errors.New("http: named cookie not present")当没有位置标题时，ErrNoLocation由Response's Location方法返回。
var ErrNoLocation = errors.New("http: no Location header in response")在调用Shutdown或Close之后，服务器的Serve，ServeTLS，ListenAndServe和ListenAndServeTLS方法会返回ErrServerClosed。
var ErrServerClosed = errors.New("http: Server closed")ErrSkipAltProtocol是由Transport.RegisterProtocol定义的一个sentinel错误值。
var ErrSkipAltProtocol = errors.New("net/http: skip alternate protocol")Client.CheckRedirect钩子可以返回ErrUseLastResponse来控制重定向的处理方式。如果返回，则不会发送下一个请求，并且返回其最新的响应，并且其主体未关闭。
var ErrUseLastResponse = errors.New("net/http: use last response")NoBody是一个没有字节的io.ReadCloser。阅读始终返回EOF和关闭总是返回零。它可用于传出的客户端请求中，以明确表示请求具有零字节。但是，另一种方法是简单地将Request.Body设置为零。
var NoBody = noBody{}func CanonicalHeaderKey
func CanonicalHeaderKey(s string) string
CanonicalHeaderKey返回标题密钥的规范格式。规范化将第一个字母和连字符后面的任何字母转换为大写；其余的都转换为小写。例如，“accept-encoding”的规范密钥是“Accept-Encoding”。如果s包含空格或无效标题字段字节，则不做任何修改就返回。
func DetectContentType
func DetectContentType(data []byte) string
DetectContentType实现http://mimesniff.spec.whatwg.org/中描述的算法来确定给定数据的内容类型。它至多会考虑前512个字节的数据。DetectContentType始终返回一个有效的MIME类型：如果无法确定更具体的MIME类型，则返回“application/octet-stream”。
func Error
func Error(w ResponseWriter, error string, code int)
错误以指定的错误消息和HTTP代码答复请求。它不以其他方式结束请求；调用者应该确保没有进一步写入w。错误信息应该是纯文本。
func Handle
func Handle(pattern string, handler Handler)
Handle将给定模式的处理程序注册到DefaultServeMux中。ServeMux的文档解释了模式如何匹配。
func HandleFunc
func HandleFunc(pattern string, handler func(ResponseWriter, *Request))
HandleFunc在DefaultServeMux中为给定模式注册处理函数。ServeMux的文档解释了模式如何匹配。
func ListenAndServe
func ListenAndServe(addr string, handler Handler) error
ListenAndServe侦听TCP网络地址addr，然后使用处理程序调用Serve来处理传入连接上的请求。接受的连接被配置为启用TCP保持活动。Handler通常为零，在这种情况下使用DefaultServeMux。
一个简单的示例服务器是：
package mainimport ("io""net/http""log")// hello world, the web serverfunc HelloServer(w http.ResponseWriter, req *http.Request) {
io.WriteString(w, "hello, world!\n")}func main() {
http.HandleFunc("/hello", HelloServer)
log.Fatal(http.ListenAndServe(":12345", nil))}ListenAndServe总是返回一个非零错误。
func ListenAndServeTLS
func ListenAndServeTLS(addr, certFile, keyFile string, handler Handler) error
ListenAndServeTLS的作用与ListenAndServe完全相同，只不过它需要HTTPS连接。此外，必须提供包含服务器证书和匹配私钥的文件。如果证书由证书颁发机构签署，则certFile应该是服务器证书，任何中间器和CA证书的串联。
一个简单的示例服务器是：
import ("log""net/http")func handler(w http.ResponseWriter, req *http.Request) {
w.Header().Set("Content-Type", "text/plain")
w.Write([]byte("This is an example server.\n"))}func main() {
http.HandleFunc("/", handler)
log.Printf("About to listen on 10443. Go to https://127.0.0.1:10443/")
err := http.ListenAndServeTLS(":10443", "cert.pem", "key.pem", nil)
log.Fatal(err)}可以使用crypto/tls中的generate_cert.go来生成cert.pem和key.pem。
ListenAndServeTLS总是返回一个非零错误。
func MaxBytesReader
func MaxBytesReader(w ResponseWriter, r io.ReadCloser, n int64) io.ReadCloser
MaxBytesReader与io.LimitReader类似，但是用于限制传入请求体的大小。与io.LimitReader相反，MaxBytesReader的结果是一个ReadCloser，它为超出限制的Read返回一个非EOF错误，并在其Close方法被调用时关闭底层的阅读器。
MaxBytesReader可防止客户端意外或恶意发送大量请求并浪费服务器资源。
func NotFound
func NotFound(w ResponseWriter, r *Request)
NotFound使用HTTP 404找不到错误来回复请求。
func ParseHTTPVersion
func ParseHTTPVersion(vers string) (major, minor int, ok bool)
ParseHTTPVersion分析HTTP版本字符串。“HTTP/1.0”返回（1, 0, true）。
func ParseTime
func ParseTime(text string) (t time.Time, err error)
ParseTime分析时间标题（例如Date: header），尝试HTTP/1.1允许的三种格式：TimeFormat，time.RFC850和time.ANSIC。
func ProxyFromEnvironment
func ProxyFromEnvironment(req *Request) (*url.URL, error)
ProxyFromEnvironment返回用于给定请求的代理的URL，如环境变量HTTP_PROXY，HTTPS_PROXY和NO_PROXY（或其小写版本）所示。对于https请求，HTTPS_PROXY优先于HTTP_PROXY。
环境值可以是完整的URL或“host:port”，在这种情况下，假设“http”方案。如果值是不同的形式，则返回错误。
如果没有在环境中定义代理，或者代理不应该用于给定请求（如NO_PROXY所定义），则返回零URL和零错误。
作为一种特殊情况，如果req.URL.Host是“localhost”（带或不带端口号），则会返回一个零URL和零错误。
func ProxyURL
func ProxyURL(fixedURL *url.URL) func(*Request) (*url.URL, error)
ProxyURL返回一个总是返回相同URL的代理函数（用于传输）。
func Redirect
func Redirect(w ResponseWriter, r *Request, url string, code int)
将重定向到url的请求重定向到请求，url可能是相对于请求路径的路径。
提供的代码应该位于3xx范围内，通常是StatusMovedPermanently，StatusFound或StatusSeeOther。
func Serve
func Serve(l net.Listener, handler Handler) error
Serve接受侦听器l上的传入HTTP连接，为每个服务器创建一个新的服务程序。服务程序读取请求，然后调用处理程序来回复它们。Handler通常为零，在这种情况下使用DefaultServeMux。
func ServeContent
func ServeContent(w ResponseWriter, req *Request, name string, modtime time.Time, content io.ReadSeeker)
ServeContent使用提供的ReadSeeker中的内容答复请求。ServeContent优于io.Copy的主要好处是它正确处理Range请求，设置MIME类型，并处理If-Match，If-Unmodified-Since，If-None-Match，If-Modified-Since和If-Range要求。
如果未设置响应的Content-Type标头，则ServeContent首先尝试从名称的文件扩展名中推导出该类型，如果失败，则返回读取内容的第一个块并将其传递给DetectContentType。这个名字是没有用的；特别是它可以是空的，并且不会在响应中发送。
如果modtime不是零时间或Unix纪元，则ServeContent将其包含在响应中的Last-Modified标头中。如果请求包含If-Modified-Since标头，则ServeContent使用modtime决定是否需要发送内容。
内容的Seek方法必须工作：ServeContent使用搜索到内容的结尾来确定其大小。
如果调用者已经根据RFC 7232第2.3节设置了w的ETag头，则ServeContent使用它来处理使用If-Match，If-None-Match或If-Range的请求。
请注意* os.File实现了io.ReadSeeker接口。
func ServeFile
func ServeFile(w ResponseWriter, r *Request, name string)
ServeFile使用指定文件或目录的内容答复请求。
如果提供的文件或目录名称是相对路径，则相对于当前目录进行解释并可能上升到父目录。如果提供的名称是从用户输入构建的，则应在调用ServeFile之前对其进行消毒。作为预防措施，ServeFile将拒绝r.URL.Path包含“..”路径元素的请求。
作为一种特殊情况，ServeFile将r.URL.Path以“/index.html”结尾的任何请求重定向到相同的路径，而没有最终的“index.html”。要避免这种重定向，请修改路径或使用ServeContent。
func ServeTLS
func ServeTLS(l net.Listener, handler Handler, certFile, keyFile string) error
Serve接受listener l上的传入HTTPS连接，为每个服务器创建一个新的服务程序。服务程序读取请求，然后调用处理程序来回复它们。
Handler通常为零，在这种情况下使用DefaultServeMux。
此外，必须提供包含服务器证书和匹配私钥的文件。如果证书由证书颁发机构签署，则certFile应该是服务器证书，任何中间器和CA证书的串联。
func SetCookie
func SetCookie(w ResponseWriter, cookie *Cookie)
SetCookie将一个Set-Cookie头添加到提供的ResponseWriter的头文件中。提供的cookie必须具有有效的名称。无效的Cookie可能会悄悄丢弃。
func StatusText
func StatusText(code int) string
StatusText返回HTTP状态码的文本。如果代码未知，它将返回空字符串。
type Client
客户端是一个HTTP客户端。其零值（DefaultClient）是使用DefaultTransport的可用客户端。
客户端的传输通常具有内部状态（缓存的TCP连接），因此客户端应该被重用，而不是根据需要创建。客户端可以安全地由多个goroutine并发使用。
客户端比RoundTripper（比如Transport）更高级，并且还处理诸如cookie和重定向之类的HTTP细节。
在重定向之后，客户端将转发在初始请求中设置的所有标头，除了：
•将“Authorization”，“WWW-Authenticate”和“Cookie”等敏感标头转发给不受信任的目标时。在重定向到不是子域匹配的域或初始域的完全匹配时，这些标头将被忽略。例如，从“foo.com”到“foo.com”或“sub.foo.com”的重定向将转发敏感标题，但重定向到“bar.com”则不会。
•转发“Cookie”标头时使用非零 cookie Jar。由于每个重定向可能会改变cookie jar的状态，重定向可能会改变初始请求中设置的cookie。转发“Cookie”标头时，任何突变的Cookie都将被忽略，并期望Jar将插入这些带有更新值的突变cookie（假设该匹配的来源）。如果Jar为零，则最初的cookie将不发送更改。
type Client struct { // Transport specifies the mechanism by which individual // HTTP requests are made. // If nil, DefaultTransport is used.
Transport RoundTripper // CheckRedirect specifies the policy for handling redirects. // If CheckRedirect is not nil, the client calls it before // following an HTTP redirect. The arguments req and via are // the upcoming request and the requests made already, oldest // first. If CheckRedirect returns an error, the Client's Get // method returns both the previous Response (with its Body // closed) and CheckRedirect's error (wrapped in a url.Error) // instead of issuing the Request req. // As a special case, if CheckRedirect returns ErrUseLastResponse, // then the most recent response is returned with its body // unclosed, along with a nil error. // // If CheckRedirect is nil, the Client uses its default policy, // which is to stop after 10 consecutive requests.
CheckRedirect func(req *Request, via []*Request) error // Jar specifies the cookie jar. // // The Jar is used to insert relevant cookies into every // outbound Request and is updated with the cookie values // of every inbound Response. The Jar is consulted for every // redirect that the Client follows. // // If Jar is nil, cookies are only sent if they are explicitly // set on the Request.
Jar CookieJar // Timeout specifies a time limit for requests made by this // Client. The timeout includes connection time, any // redirects, and reading the response body. The timer remains // running after Get, Head, Post, or Do return and will // interrupt reading of the Response.Body. // // A Timeout of zero means no timeout. // // The Client cancels requests to the underlying Transport // using the Request.Cancel mechanism. Requests passed // to Client.Do may still set Request.Cancel; both will // cancel the request. // // For compatibility, the Client will also use the deprecated // CancelRequest method on Transport if found. New // RoundTripper implementations should use Request.Cancel // instead of implementing CancelRequest.
Timeout time.Duration}func (*Client) Do
func (c *Client) Do(req *Request) (*Response, error)
不要发送HTTP请求，并按照客户端上配置的策略（例如redirects， cookies，auth）返回HTTP响应。
如果由客户端策略（如CheckRedirect）引起，或者无法说出HTTP（如网络连接问题），则返回错误。非2xx状态码不会导致错误。
如果返回的错误为零，则Response将包含一个非零体，用户需要关闭。如果Body尚未关闭，则客户端的底层RoundTripper（通常是Transport）可能无法重新使用持久性TCP连接到服务器以进行后续“保持活动”请求。
如果非零，请求主体将被底层传输关闭，即使出现错误。
出错时，可以忽略任何响应。非零错误的非零响应仅在CheckRedirect失败时发生，即使返回的Response.Body已经关闭。
通常会使用Get，Post或PostForm来代替Do.
如果服务器回复重定向，则客户端首先使用CheckRedirect函数确定是否应该遵循重定向。如果允许，301,302或303重定向会导致后续请求使用HTTP方法GET（如果原始请求是HEAD，则为HEAD），但不包含主体。只要定义了Request.GetBody函数，307或308重定向就会保留原始的HTTP方法和主体。NewRequest函数自动为通用标准库体类型设置GetBody。
func (*Client) Get
func (c *Client) Get(url string) (resp *Response, err error)
将问题GET获取到指定的URL。如果响应是以下重定向代码之一，则在调用客户端的CheckRedirect函数后，Get遵循重定向：
301 (Moved Permanently)302 (Found)303 (See Other)307 (Temporary Redirect)308 (Permanent Redirect)
如果客户端的CheckRedirect功能失败或者出现HTTP协议错误，则返回错误。非2xx响应不会导致错误。
当err为零时，resp总是包含非零的resp.Body。来电者在完成阅读后应关闭resp.Body。
要使用自定义标题发出请求，请使用NewRequest和Client.Do。
func (*Client) Head
func (c *Client) Head(url string) (resp *Response, err error)
Head向指定的URL发出HEAD。如果响应是以下重定向代码之一，则Head在调用客户端的CheckRedirect函数后遵循重定向：
301 (Moved Permanently)302 (Found)303 (See Other)307 (Temporary Redirect)308 (Permanent Redirect)
func (*Client) Post
func (c *Client) Post(url string, contentType string, body io.Reader) (resp *Response, err error)
发布POST到指定的URL。
调用者在完成阅读后应关闭resp.Body。
如果提供的主体是io.Closer，则在请求后关闭。
要设置自定义标题，请使用NewRequest和Client.Do。
有关如何处理重定向的详细信息，请参阅Client.Do方法文档。
func (*Client) PostForm
func (c *Client) PostForm(url string, data url.Values) (resp *Response, err error)
PostForm向指定的URL发布POST，并将数据的键和值作为请求主体进行URL编码。
Content-Type头部设置为application/x-www-form-urlencoded。要设置其他标题，请使用NewRequest和DefaultClient.Do。
当err为零时，resp总是包含非零的resp.Body。调用者在完成阅读后应关闭resp.Body。
有关如何处理重定向的详细信息，请参阅Client.Do方法文档。
type CloseNotifier
CloseNotifier接口由ResponseWriters实现，它允许检测基础连接何时消失。
如果客户端在响应准备好之前断开连接，则可以使用此机制取消服务器上的长时间操作。
type CloseNotifier interface { // CloseNotify returns a channel that receives at most a // single value (true) when the client connection has gone // away. // // CloseNotify may wait to notify until Request.Body has been // fully read. // // After the Handler has returned, there is no guarantee // that the channel receives a value. // // If the protocol is HTTP/1.1 and CloseNotify is called while // processing an idempotent request (such a GET) while // HTTP/1.1 pipelining is in use, the arrival of a subsequent // pipelined request may cause a value to be sent on the // returned channel. In practice HTTP/1.1 pipelining is not // enabled in browsers and not seen often in the wild. If this // is a problem, use HTTP/2 or only use CloseNotify on methods // such as POST. CloseNotify() <-chan bool}type ConnState
ConnState表示客户端连接到服务器的状态。它由可选的Server.ConnState挂钩使用。
type ConnState int
const ( // StateNew represents a new connection that is expected to // send a request immediately. Connections begin at this // state and then transition to either StateActive or // StateClosed. StateNew ConnState = iota // StateActive represents a connection that has read 1 or more // bytes of a request. The Server.ConnState hook for // StateActive fires before the request has entered a handler // and doesn't fire again until the request has been // handled. After the request is handled, the state // transitions to StateClosed, StateHijacked, or StateIdle. // For HTTP/2, StateActive fires on the transition from zero // to one active request, and only transitions away once all // active requests are complete. That means that ConnState // cannot be used to do per-request work; ConnState only notes // the overall state of the connection. StateActive // StateIdle represents a connection that has finished // handling a request and is in the keep-alive state, waiting // for a new request. Connections transition from StateIdle // to either StateActive or StateClosed. StateIdle // StateHijacked represents a hijacked connection. // This is a terminal state. It does not transition to StateClosed. StateHijacked // StateClosed represents a closed connection. // This is a terminal state. Hijacked connections do not // transition to StateClosed. StateClosed)
func (ConnState) String
func (c ConnState) String() string
type Cookie
Cookie表示HTTP响应的Set-Cookie头或HTTP请求的Cookie头中发送的HTTP cookie。
type Cookie struct {
Name string
Value string
Path string // optional
Domain string // optional
Expires time.Time // optional
RawExpires string // for reading cookies only // MaxAge=0 means no 'Max-Age' attribute specified. // MaxAge<0 means delete cookie now, equivalently 'Max-Age: 0' // MaxAge>0 means Max-Age attribute present and given in seconds
MaxAge int
Secure bool
HttpOnly bool
Raw string
Unparsed []string // Raw text of unparsed attribute-value pairs}func (*Cookie) String
func (c *Cookie) String() string
字符串返回用于Cookie标头（如果仅设置了Name和Value）或Set-Cookie响应标头（如果设置了其他字段）的Cookie的序列化。如果c为零或c.Name无效，则返回空字符串。
type CookieJar
CookieJar管理HTTP请求中cookie的存储和使用。
CookieJar的实现必须安全，以供多个goroutine同时使用。
net/http/cookiejar包提供了一个CookieJar实现。
type CookieJar interface { // SetCookies handles the receipt of the cookies in a reply for the // given URL. It may or may not choose to save the cookies, depending // on the jar's policy and implementation. SetCookies(u *url.URL, cookies []*Cookie) // Cookies returns the cookies to send in a request for the given URL. // It is up to the implementation to honor the standard cookie use // restrictions such as in RFC 6265. Cookies(u *url.URL) []*Cookie}type Dir
Dir使用限于特定目录树的本机文件系统实现FileSystem。
虽然FileSystem.Open方法采用'/' - 分隔的路径，但Dir的字符串值是本地文件系统上的文件名，而不是URL，因此它由filepath.Separator分隔，而不一定是'/'。
请注意，Dir将允许访问以句点开头的文件和目录，这可能会暴露敏感目录（如.git目录）或敏感文件（如.htpasswd）。要排除具有前导期的文件，请从服务器中删除文件/目录或创建自定义FileSystem实现。
空的Dir被视为“。”。
type Dir string
func (Dir) Open
func (d Dir) Open(name string) (File, error)
type File
File由FileSystem的Open方法返回，并可由FileServer实现提供。
这些方法的行为应该与* os.File中的方法相同。
type File interface {
io.Closer
io.Reader
io.Seeker Readdir(count int) ([]os.FileInfo, error) Stat() (os.FileInfo, error)}type FileSystem
FileSystem实现对指定文件集合的访问。无论主机操作系统惯例如何，文件路径中的元素都用斜线（'/', U+002F）字符分隔。
type FileSystem interface { Open(name string) (File, error)}type Flusher
Flusher接口由ResponseWriters实现，它允许HTTP处理器将缓冲数据刷新到客户端。
默认的HTTP/1.x和HTTP/2 ResponseWriter实现支持Flusher，但ResponseWriter包装可能不支持。处理程序应始终在运行时测试此功能。
请注意，即使对于支持Flush的ResponseWriters，如果客户端通过HTTP代理连接，缓存的数据可能无法到达客户端，直到响应完成。
type Flusher interface { // Flush sends any buffered data to the client. Flush()}type Handler
Handler响应HTTP请求。
ServeHTTP应该将回复头文件和数据写入ResponseWriter，然后返回。返回请求完成的信号；在完成ServeHTTP调用之后或同时完成使用ResponseWriter或从Request.Body中读取是无效的。
根据HTTP客户端软件，HTTP协议版本以及客户端与Go服务器之间的任何中介，在写入ResponseWriter后，可能无法从Request.Body中读取数据。谨慎的处理程序应先读取Request.Body，然后回复。
除阅读主体外，处理程序不应修改提供的请求。
如果ServeHTTP发生混乱，则服务器（ServeHTTP的调用者）认为恐慌的影响与活动请求分离。它恢复恐慌，将堆栈跟踪记录到服务器错误日志中，并根据HTTP协议关闭网络连接或发送HTTP/2 RST_STREAM。要终止处理程序，以便客户端看到中断的响应，但服务器不记录错误，请使用值ErrAbortHandler恐慌。
type Handler interface { ServeHTTP(ResponseWriter, *Request)}func FileServer
func FileServer(root FileSystem) Handler
FileServer返回一个处理程序，该处理程序为root用户提供文件系统内容的HTTP请求。
要使用操作系统的文件系统实现，请使用http.Dir：
http.Handle("/", http.FileServer(http.Dir("/tmp")))作为一种特殊情况，返回的文件服务器将以“/index.html”结尾的任何请求重定向到相同的路径，而没有最终的“index.html”。
示例
package mainimport ("log""net/http")func main() {// Simple static webserver:
log.Fatal(http.ListenAndServe(":8080", http.FileServer(http.Dir("/usr/share/doc"))))}示例（StripPrefix）
package mainimport ("net/http")func main() {// To serve a directory on disk (/tmp) under an alternate URL// path (/tmpfiles/), use StripPrefix to modify the request// URL's path before the FileServer sees it:
http.Handle("/tmpfiles/", http.StripPrefix("/tmpfiles/", http.FileServer(http.Dir("/tmp"))))}func NotFoundHandler
func NotFoundHandler() Handler
NotFoundHandler返回一个简单的请求处理程序，用于处理每个请求的“404页未找到”答复。
func RedirectHandler
func RedirectHandler(url string, code int) Handler
RedirectHandler返回一个请求处理程序，它使用给定的状态码将其收到的每个请求重定向到给定的url。
提供的代码应该位于3xx范围内，通常是StatusMovedPermanently，StatusFound或StatusSeeOther。
func StripPrefix
func StripPrefix(prefix string, h Handler) Handler
StripPrefix通过从请求URL的Path中移除给定的前缀并调用处理程序h来返回一个处理程序，该处理程序提供HTTP请求。StripPrefix通过回答HTTP 404找不到错误来处理对不以前缀开头的路径的请求。
示例
package mainimport ("net/http")func main() {// To serve a directory on disk (/tmp) under an alternate URL// path (/tmpfiles/), use StripPrefix to modify the request// URL's path before the FileServer sees it:
http.Handle("/tmpfiles/", http.StripPrefix("/tmpfiles/", http.FileServer(http.Dir("/tmp"))))}func TimeoutHandler
func TimeoutHandler(h Handler, dt time.Duration, msg string) Handler
TimeoutHandler返回一个处理器，它在给定的时间限制内运行h。
新的Handler调用h.ServeHTTP来处理每个请求，但是如果一个调用的运行时间超过其时间限制，处理程序会响应503服务不可用错误和其正文中的给定消息。（如果msg为空，将发送一个合适的默认消息。）在这样的超时之后，h写入其ResponseWriter将返回ErrHandlerTimeout。
TimeoutHandler将所有Handler缓冲区写入内存，并且不支持Hijacker或Flusher接口。
type HandlerFunc
HandlerFunc类型是一个适配器，允许使用普通函数作为HTTP处理程序。如果f是具有适当签名的函数，则HandlerFunc(f)是调用f的Handler。
type HandlerFunc func(ResponseWriter, *Request)
func (HandlerFunc) ServeHTTP
func (f HandlerFunc) ServeHTTP(w ResponseWriter, r *Request)
ServeHTTP calls f(w, r).
type Header
标题表示HTTP标题中的键值对。
type Header map[string][]string
func (Header) Add
func (h Header) Add(key, value string)
添加将关键字值对添加到标题。它附加到与键相关的任何现有值。
func (Header) Del
func (h Header) Del(key string)
Del删除与键关联的值。
func (Header) Get
func (h Header) Get(key string) string
获取与给定键相关的第一个值。它不区分大小写; textproto.CanonicalMIMEHeaderKey用于规范提供的密钥。如果没有与该键关联的值，Get返回“”。要访问密钥的多个值或使用非规范密钥，请直接访问地图。
func (Header) Set
func (h Header) Set(key, value string)
Set将与键关联的标题条目设置为单个元素值。它取代了任何与键相关的现有值。
func (Header) Write
func (h Header) Write(w io.Writer) error
Write以格式写入标题。
func (Header) WriteSubset
func (h Header) WriteSubset(w io.Writer, exclude map[string]bool) error
WriteSubset以连线格式写入标题。如果exclude不为零，则不会写入excludekey == true的键。
type Hijacker
Hijacker接口由ResponseWriters实现，它允许HTTP处理程序接管连接。
HTTP/1.x连接的默认ResponseWriter支持劫持程序，但HTTP/2连接故意不支持。ResponseWriter包装器也可能不支持劫持程序。处理程序应始终在运行时测试此功能。
type Hijacker interface { // Hijack lets the caller take over the connection. // After a call to Hijack the HTTP server library // will not do anything else with the connection. // // It becomes the caller's responsibility to manage // and close the connection. // // The returned net.Conn may have read or write deadlines // already set, depending on the configuration of the // Server. It is the caller's responsibility to set // or clear those deadlines as needed. // // The returned bufio.Reader may contain unprocessed buffered // data from the client. // // After a call to Hijack, the original Request.Body should // not be used. Hijack() (net.Conn, *bufio.ReadWriter, error)}示例
package mainimport ("fmt""log""net/http")func main() {
http.HandleFunc("/hijack", func(w http.ResponseWriter, r *http.Request) {
hj, ok := w.(http.Hijacker)if !ok {
http.Error(w, "webserver doesn't support hijacking", http.StatusInternalServerError)return}
conn, bufrw, err := hj.Hijack()if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)return}// Don't forget to close the connection:
defer conn.Close()
bufrw.WriteString("Now we're speaking raw TCP. Say hi: ")
bufrw.Flush()
s, err := bufrw.ReadString('\n')if err != nil {
log.Printf("error reading string: %v", err)return}
fmt.Fprintf(bufrw, "You said: %q\nBye.\n", s)
bufrw.Flush()})}type ProtocolError
ProtocolError表示HTTP协议错误。
Deprecated：并非与协议错误有关的http包中的所有错误都是ProtocolError 类型。
type ProtocolError struct {
ErrorString string}func (*ProtocolError) Error
func (pe *ProtocolError) Error() string
type PushOptions
PushOptions描述了Pusher.Push的选项。
type PushOptions struct { // Method specifies the HTTP method for the promised request. // If set, it must be "GET" or "HEAD". Empty means "GET".
Method string // Header specifies additional promised request headers. This cannot // include HTTP/2 pseudo header fields like ":path" and ":scheme", // which will be added automatically.
Header Header}type Pusher
Pusher是ResponseWriters实现的接口，支持HTTP/2服务器推送。
type Pusher interface { // Push initiates an HTTP/2 server push. This constructs a synthetic // request using the given target and options, serializes that request // into a PUSH_PROMISE frame, then dispatches that request using the // server's request handler. If opts is nil, default options are used. // // The target must either be an absolute path (like "/path") or an absolute // URL that contains a valid host and the same scheme as the parent request. // If the target is a path, it will inherit the scheme and host of the // parent request. // // The HTTP/2 spec disallows recursive pushes and cross-authority pushes. // Push may or may not detect these invalid pushes; however, invalid // pushes will be detected and canceled by conforming clients. // // Handlers that wish to push URL X should call Push before sending any // data that may trigger a request for URL X. This avoids a race where the // client issues requests for X before receiving the PUSH_PROMISE for X. // // Push returns ErrNotSupported if the client has disabled push or if push // is not supported on the underlying connection. Push(target string, opts *PushOptions) error}type Request
请求表示由服务器接收或由客户端发送的HTTP请求。
客户端和服务器使用情况的字段语义略有不同。除了下面字段的注释之外，请参阅Request.Write和RoundTripper的文档。
type Request struct { // Method specifies the HTTP method (GET, POST, PUT, etc.). // For client requests an empty string means GET.
Method string // URL specifies either the URI being requested (for server // requests) or the URL to access (for client requests). // // For server requests the URL is parsed from the URI // supplied on the Request-Line as stored in RequestURI. For // most requests, fields other than Path and RawQuery will be // empty. (See RFC 2616, Section 5.1.2) // // For client requests, the URL's Host specifies the server to // connect to, while the Request's Host field optionally // specifies the Host header value to send in the HTTP // request.
URL *url.URL // The protocol version for incoming server requests. // // For client requests these fields are ignored. The HTTP // client code always uses either HTTP/1.1 or HTTP/2. // See the docs on Transport for details.
Proto string // "HTTP/1.0"
ProtoMajor int // 1
ProtoMinor int // 0 // Header contains the request header fields either received // by the server or to be sent by the client. // // If a server received a request with header lines, // // Host: example.com // accept-encoding: gzip, deflate // Accept-Language: en-us // fOO: Bar // foo: two // // then // // Header = map[string][]string{ // "Accept-Encoding": {"gzip, deflate"}, // "Accept-Language": {"en-us"}, // "Foo": {"Bar", "two"}, // } // // For incoming requests, the Host header is promoted to the // Request.Host field and removed from the Header map. // // HTTP defines that header names are case-insensitive. The // request parser implements this by using CanonicalHeaderKey, // making the first character and any characters following a // hyphen uppercase and the rest lowercase. // // For client requests, certain headers such as Content-Length // and Connection are automatically written when needed and // values in Header may be ignored. See the documentation // for the Request.Write method.
Header Header // Body is the request's body. // // For client requests a nil body means the request has no // body, such as a GET request. The HTTP Client's Transport // is responsible for calling the Close method. // // For server requests the Request Body is always non-nil // but will return EOF immediately when no body is present. // The Server will close the request body. The ServeHTTP // Handler does not need to.
Body io.ReadCloser // GetBody defines an optional func to return a new copy of // Body. It is used for client requests when a redirect requires // reading the body more than once. Use of GetBody still // requires setting Body. // // For server requests it is unused.
GetBody func() (io.ReadCloser, error) // ContentLength records the length of the associated content. // The value -1 indicates that the length is unknown. // Values >= 0 indicate that the given number of bytes may // be read from Body. // For client requests, a value of 0 with a non-nil Body is // also treated as unknown.
ContentLength int64 // TransferEncoding lists the transfer encodings from outermost to // innermost. An empty list denotes the "identity" encoding. // TransferEncoding can usually be ignored; chunked encoding is // automatically added and removed as necessary when sending and // receiving requests.
TransferEncoding []string // Close indicates whether to close the connection after // replying to this request (for servers) or after sending this // request and reading its response (for clients). // // For server requests, the HTTP server handles this automatically // and this field is not needed by Handlers. // // For client requests, setting this field prevents re-use of // TCP connections between requests to the same hosts, as if // Transport.DisableKeepAlives were set.
Close bool // For server requests Host specifies the host on which the // URL is sought. Per RFC 2616, this is either the value of // the "Host" header or the host name given in the URL itself. // It may be of the form "host:port". For international domain // names, Host may be in Punycode or Unicode form. Use // golang.org/x/net/idna to convert it to either format if // needed. // // For client requests Host optionally overrides the Host // header to send. If empty, the Request.Write method uses // the value of URL.Host. Host may contain an international // domain name.
Host string // Form contains the parsed form data, including both the URL // field's query parameters and the POST or PUT form data. // This field is only available after ParseForm is called. // The HTTP client ignores Form and uses Body instead.
Form url.Values // PostForm contains the parsed form data from POST, PATCH, // or PUT body parameters. // // This field is only available after ParseForm is called. // The HTTP client ignores PostForm and uses Body instead.
PostForm url.Values // MultipartForm is the parsed multipart form, including file uploads. // This field is only available after ParseMultipartForm is called. // The HTTP client ignores MultipartForm and uses Body instead.
MultipartForm *multipart.Form // Trailer specifies additional headers that are sent after the request // body. // // For server requests the Trailer map initially contains only the // trailer keys, with nil values. (The client declares which trailers it // will later send.) While the handler is reading from Body, it must // not reference Trailer. After reading from Body returns EOF, Trailer // can be read again and will contain non-nil values, if they were sent // by the client. // // For client requests Trailer must be initialized to a map containing // the trailer keys to later send. The values may be nil or their final // values. The ContentLength must be 0 or -1, to send a chunked request. // After the HTTP request is sent the map values can be updated while // the request body is read. Once the body returns EOF, the caller must // not mutate Trailer. // // Few HTTP clients, servers, or proxies support HTTP trailers.
Trailer Header // RemoteAddr allows HTTP servers and other software to record // the network address that sent the request, usually for // logging. This field is not filled in by ReadRequest and // has no defined format. The HTTP server in this package // sets RemoteAddr to an "IP:port" address before invoking a // handler. // This field is ignored by the HTTP client.
RemoteAddr string // RequestURI is the unmodified Request-URI of the // Request-Line (RFC 2616, Section 5.1) as sent by the client // to a server. Usually the URL field should be used instead. // It is an error to set this field in an HTTP client request.
RequestURI string // TLS allows HTTP servers and other software to record // information about the TLS connection on which the request // was received. This field is not filled in by ReadRequest. // The HTTP server in this package sets the field for // TLS-enabled connections before invoking a handler; // otherwise it leaves the field nil. // This field is ignored by the HTTP client.
TLS *tls.ConnectionState // Cancel is an optional channel whose closure indicates that the client // request should be regarded as canceled. Not all implementations of // RoundTripper may support Cancel. // // For server requests, this field is not applicable. // // Deprecated: Use the Context and WithContext methods // instead. If a Request's Cancel field and context are both // set, it is undefined whether Cancel is respected.
Cancel <-chan struct{} // Response is the redirect response which caused this request // to be created. This field is only populated during client // redirects.
Response *Response // contains filtered or unexported fields}func NewRequest
func NewRequest(method, url string, body io.Reader) (*Request, error)
NewRequest返回给定方法，URL和可选主体的新请求。
如果提供的主体也是io.Closer，则返回的Request.Body将设置为body，并且将由客户端方法Do，Post和PostForm以及Transport.RoundTrip关闭。
NewRequest返回适用于Client.Do或Transport.RoundTrip的请求。要创建与测试服务器处理程序一起使用的请求，请使用net/http/httptest软件包中的NewRequest函数，使用ReadRequest或手动更新请求字段。有关入站和出站请求字段之间的差异，请参阅请求类型的文档。
如果body是* bytes.Buffer，* bytes.Reader或* strings.Reader类型，则返回的请求的ContentLength被设置为它的精确值（而不是-1），GetBody被填充（所以307和308重定向可以重放body），如果ContentLength为0，则Body设置为NoBody。
func ReadRequest
func ReadRequest(b *bufio.Reader) (*Request, error)
ReadRequest读取并解析来自b的传入请求。
func (*Request) AddCookie
func (r *Request) AddCookie(c *Cookie)
AddCookie向请求添加一个cookie。根据RFC 6265第5.4节的规定，AddCookie不会附加多个Cookie标题字段。这意味着所有的cookies（如果有的话）被写入同一行，并以分号分隔。
func (*Request) BasicAuth
func (r *Request) BasicAuth() (username, password string, ok bool)
如果请求使用HTTP基本认证，BasicAuth将返回请求的授权标头中提供的用户名和密码。请参阅RFC 2617，第2部分。
func (*Request) Context
func (r *Request) Context() context.Context
上下文返回请求的上下文。要更改上下文，请使用WithContext。
返回的上下文总是非零；它默认为后台上下文。
对于传出的客户端请求，上下文控制取消。
对于传入的服务器请求，当客户端连接关闭，取消请求（使用HTTP/2）或ServeHTTP方法返回时，上下文将被取消。
func (*Request) Cookie
func (r *Request) Cookie(name string) (*Cookie, error)
Cookie返回请求中提供的命名cookie或ErrNoCookie，如果未找到。如果多个cookie匹配给定名称，则只会返回一个cookie。
func (*Request) Cookies
func (r *Request) Cookies() []*Cookie
Cookies解析并返回随请求发送的HTTP Cookie。
func (*Request) FormFile
func (r *Request) FormFile(key string) (multipart.File, *multipart.FileHeader, error)
FormFile返回提供的表单键的第一个文件。如有必要，FormFile调用ParseMultipartForm和ParseForm。
func (*Request) FormValue
func (r *Request) FormValue(key string) string
FormValue返回查询命名组件的第一个值。POST和PUT正文参数优先于URL查询字符串值。如有必要，FormValue调用ParseMultipartForm和ParseForm，并忽略这些函数返回的任何错误。如果键不存在，FormValue返回空字符串。要访问同一个键的多个值，请调用ParseForm，然后直接检查Request.Form。
func (*Request) MultipartReader
func (r *Request) MultipartReader() (*multipart.Reader, error)
如果这是multipart/form-data POST请求，则MultipartReader会返回MIME多部分阅读器，否则返回nil并显示错误。使用此函数而不是ParseMultipartForm将请求主体作为流处理。
func (*Request) ParseForm
func (r *Request) ParseForm() error
ParseForm填充r.Form和r.PostForm。
对于所有请求，ParseForm解析来自URL的原始查询并更新r.Form。
对于POST，PUT和PATCH请求，它还将请求主体解析为表单并将结果放入r.PostForm和r.Form中。请求主体参数优先于r.Form中的URL查询字符串值。
对于其他HTTP方法，或者当Content-Type不是application/x-www-form-urlencoded时，请求体不会被读取，并且r.PostForm被初始化为非零空值。
如果请求体的大小尚未被MaxBytesReader限制，则大小限制为10MB。
ParseMultipartForm自动调用ParseForm。ParseForm是幂等的。
func (*Request) ParseMultipartForm
func (r *Request) ParseMultipartForm(maxMemory int64) error
ParseMultipartForm将请求主体解析为multipart/form-data。对整个请求体进行解析，并将其文件部分的总共maxMemory字节存储在内存中，其余部分存储在磁盘中的临时文件中。如有必要，ParseMultipartForm会调用ParseForm。在一次调用ParseMultipartForm后，后续调用不起作用。
func (*Request) PostFormValue
func (r *Request) PostFormValue(key string) string
PostFormValue返回POST或PUT请求主体的命名组件的第一个值。网址查询参数被忽略。如有必要，PostFormValue调用ParseMultipartForm和ParseForm，并忽略这些函数返回的任何错误。如果键不存在，PostFormValue返回空字符串。
func (*Request) ProtoAtLeast
func (r *Request) ProtoAtLeast(major, minor int) bool
ProtoAtLeast报告请求中使用的HTTP协议是否至少major.minor。
func (*Request) Referer
func (r *Request) Referer() string
如果在请求中发送，Referer返回引用URL。
引用者在请求本身中拼写错误，这是HTTP早期的错误。这个值也可以从Header映射中作为Header“Referer”获取; 将其作为一种方法提供的好处是，编译器可以诊断使用备用（正确的英文）拼写req.Referrer()的程序，但无法诊断使用Header“Referrer”的程序。
func (*Request) SetBasicAuth
func (r *Request) SetBasicAuth(username, password string)
SetBasicAuth将请求的授权标头设置为使用带有所提供的用户名和密码的HTTP基本认证。
使用HTTP基本身份验证时，提供的用户名和密码未加密。
func (*Request) UserAgent
func (r *Request) UserAgent() string
如果在请求中发送，UserAgent会返回客户端的用户代理。
func (*Request) WithContext
func (r *Request) WithContext(ctx context.Context) *Request
WithContext返回r的浅表副本，其上下文已更改为ctx。提供的ctx必须是非零。
func (*Request) Write
func (r *Request) Write(w io.Writer) error
写入有线格式的HTTP/1.1请求，这是标头和正文。该方法会查询请求的以下字段：
Host URLMethod (defaults to "GET")Header ContentLength TransferEncoding Body
如果Body存在，则Content-Length <= 0且TransferEncoding尚未设置为“identity”，Write将“Transfer-Encoding: chunked”添加到标头。身体在发送后关闭。
func (*Request) WriteProxy
func (r *Request) WriteProxy(w io.Writer) error
WriteProxy就像Write，但以HTTP代理的预期形式写入请求。特别是，WriteProxy按照RFC 2616的5.1.2节（包括方案和主机）以绝对URI写入请求的初始Request-URI行。无论哪种情况，WriteProxy还会使用r.Host或r.URL.Host写入一个主机头。
type Response
响应表示来自HTTP请求的响应。
type Response struct {
Status string // e.g. "200 OK"
StatusCode int // e.g. 200
Proto string // e.g. "HTTP/1.0"
ProtoMajor int // e.g. 1
ProtoMinor int // e.g. 0 // Header maps header keys to values. If the response had multiple // headers with the same key, they may be concatenated, with comma // delimiters. (Section 4.2 of RFC 2616 requires that multiple headers // be semantically equivalent to a comma-delimited sequence.) When // Header values are duplicated by other fields in this struct (e.g., // ContentLength, TransferEncoding, Trailer), the field values are // authoritative. // // Keys in the map are canonicalized (see CanonicalHeaderKey).
Header Header // Body represents the response body. // // The http Client and Transport guarantee that Body is always // non-nil, even on responses without a body or responses with // a zero-length body. It is the caller's responsibility to // close Body. The default HTTP client's Transport does not // attempt to reuse HTTP/1.0 or HTTP/1.1 TCP connections // ("keep-alive") unless the Body is read to completion and is // closed. // // The Body is automatically dechunked if the server replied // with a "chunked" Transfer-Encoding.
Body io.ReadCloser // ContentLength records the length of the associated content. The // value -1 indicates that the length is unknown. Unless Request.Method // is "HEAD", values >= 0 indicate that the given number of bytes may // be read from Body.
ContentLength int64 // Contains transfer encodings from outer-most to inner-most. Value is // nil, means that "identity" encoding is used.
TransferEncoding []string // Close records whether the header directed that the connection be // closed after reading Body. The value is advice for clients: neither // ReadResponse nor Response.Write ever closes a connection.
Close bool // Uncompressed reports whether the response was sent compressed but // was decompressed by the http package. When true, reading from // Body yields the uncompressed content instead of the compressed // content actually set from the server, ContentLength is set to -1, // and the "Content-Length" and "Content-Encoding" fields are deleted // from the responseHeader. To get the original response from // the server, set Transport.DisableCompression to true.
Uncompressed bool // Trailer maps trailer keys to values in the same // format as Header. // // The Trailer initially contains only nil values, one for // each key specified in the server's "Trailer" header // value. Those values are not added to Header. // // Trailer must not be accessed concurrently with Read calls // on the Body. // // After Body.Read has returned io.EOF, Trailer will contain // any trailer values sent by the server.
Trailer Header // Request is the request that was sent to obtain this Response. // Request's Body is nil (having already been consumed). // This is only populated for Client requests.
Request *Request // TLS contains information about the TLS connection on which the // response was received. It is nil for unencrypted responses. // The pointer is shared between responses and should not be // modified.
TLS *tls.ConnectionState}func Get
func Get(url string) (resp *Response, err error)
将问题GET获取到指定的URL。如果响应是以下重定向代码之一，则Get遵循重定向，最多可重定向10次：
301 (Moved Permanently)302 (Found)303 (See Other)307 (Temporary Redirect)308 (Permanent Redirect)
如果重定向太多或出现HTTP协议错误，则会返回错误。非2xx响应不会导致错误。
当err为零时，resp总是包含非零的resp.Body。来电者在完成阅读后应关闭resp.Body。
Get是一个DefaultClient.Get的包装器。
要使用自定义标题发出请求，请使用NewRequest和DefaultClient.Do。
示例
package mainimport ("fmt""io/ioutil""log""net/http")func main() {
res, err := http.Get("http://www.google.com/robots.txt")if err != nil {
log.Fatal(err)}
robots, err := ioutil.ReadAll(res.Body)
res.Body.Close()if err != nil {
log.Fatal(err)}
fmt.Printf("%s", robots)}func Head
func Head(url string) (resp *Response, err error)
Head向指定的URL发出HEAD。如果响应是以下重定向代码之一，Head会遵循重定向，最多可重定向10次：
301 (Moved Permanently)302 (Found)303 (See Other)307 (Temporary Redirect)308 (Permanent Redirect)
Head是DefaultClient.Head的包装
func Post
func Post(url string, contentType string, body io.Reader) (resp *Response, err error)
发布POST到指定的URL。
调用者在完成阅读后应关闭resp.Body。
如果提供的主体是io.Closer，则在请求后关闭。
Post是DefaultClient.Post的一个包装。
要设置自定义标题，请使用NewRequest和DefaultClient.Do。
有关如何处理重定向的详细信息，请参阅Client.Do方法文档。
func PostForm
func PostForm(url string, data url.Values) (resp *Response, err error)
PostForm向指定的URL发布POST，并将数据的键和值作为请求主体进行URL编码。
Content-Type头部设置为application/x-www-form-urlencoded。要设置其他标题，请使用NewRequest和DefaultClient.Do。
当err为零时，resp总是包含非零的resp.Body。调用者在完成阅读后应关闭resp.Body。
PostForm是DefaultClient.PostForm的封装。
有关如何处理重定向的详细信息，请参阅Client.Do方法文档。
func ReadResponse
func ReadResponse(r *bufio.Reader, req *Request) (*Response, error)
ReadResponse读取并返回来自r的HTTP响应。req参数可选地指定对应于此响应的请求。如果为零，则假定有GET请求。读完resp.Body后，客户必须调用resp.Body.Close。通话结束后，客户可以检查resp.Trailer以查找响应预告片中包含的key/value pairs。
func (*Response) Cookies
func (r *Response) Cookies() []*Cookie
Cookies分析并返回Set-Cookie标题中设置的Cookie。
func (*Response) Location
func (r *Response) Location() (*url.URL, error)
位置返回响应的“位置”标题的URL（如果存在）。相对重定向相对于响应的请求被解析。如果不存在位置标题，则返回ErrNoLocation。
func (*Response) ProtoAtLeast
func (r *Response) ProtoAtLeast(major, minor int) bool
ProtoAtLeast报告响应中使用的HTTP协议是否至少是major.minor。
func (*Response) Write
func (r *Response) Write(w io.Writer) error
Write r以HTTP/1.x服务器响应格式写入w，包括状态行，标题，正文和可选的trailer。
该方法参考响应r的以下字段：
StatusCode ProtoMajor ProtoMinor Request.Method TransferEncoding Trailer Body ContentLength Header, values for non-canonical keys will have unpredictable behavior
响应主体在发送后关闭。
type ResponseWriter
HTTP处理程序使用ResponseWriter接口来构造HTTP响应。
在Handler.ServeHTTP方法返回后，可能不会使用ResponseWriter。
type ResponseWriter interface { // Header returns the header map that will be sent by // WriteHeader. The Header map also is the mechanism with which // Handlers can set HTTP trailers. // // Changing the header map after a call to WriteHeader (or // Write) has no effect unless the modified headers are // trailers. // // There are two ways to set Trailers. The preferred way is to // predeclare in the headers which trailers you will later // send by setting the "Trailer" header to the names of the // trailer keys which will come later. In this case, those // keys of the Header map are treated as if they were // trailers. See the example. The second way, for trailer // keys not known to the Handler until after the first Write, // is to prefix the Header map keys with the TrailerPrefix // constant value. See TrailerPrefix. // // To suppress implicit response headers (such as "Date"), set // their value to nil. Header() Header // Write writes the data to the connection as part of an HTTP reply. // // If WriteHeader has not yet been called, Write calls // WriteHeader(http.StatusOK) before writing the data. If the Header // does not contain a Content-Type line, Write adds a Content-Type set // to the result of passing the initial 512 bytes of written data to // DetectContentType. // // Depending on the HTTP protocol version and the client, calling // Write or WriteHeader may prevent future reads on the // Request.Body. For HTTP/1.x requests, handlers should read any // needed request body data before writing the response. Once the // headers have been flushed (due to either an explicit Flusher.Flush // call or writing enough data to trigger a flush), the request body // may be unavailable. For HTTP/2 requests, the Go HTTP server permits // handlers to continue to read the request body while concurrently // writing the response. However, such behavior may not be supported // by all HTTP/2 clients. Handlers should read before writing if // possible to maximize compatibility. Write([]byte) (int, error) // WriteHeader sends an HTTP response header with status code. // If WriteHeader is not called explicitly, the first call to Write // will trigger an implicit WriteHeader(http.StatusOK). // Thus explicit calls to WriteHeader are mainly used to // send error codes. WriteHeader(int)}示例（Trailers）
HTTP Trailers是一组key/value pairs，如HTTP响应之后的headers，而不是之前。
package mainimport ("io""net/http")func main() {
mux := http.NewServeMux()
mux.HandleFunc("/sendstrailers", func(w http.ResponseWriter, req *http.Request) {// Before any call to WriteHeader or Write, declare// the trailers you will set during the HTTP// response. These three headers are actually sent in// the trailer.
w.Header().Set("Trailer", "AtEnd1, AtEnd2")
w.Header().Add("Trailer", "AtEnd3")
w.Header().Set("Content-Type", "text/plain; charset=utf-8") // normal header
w.WriteHeader(http.StatusOK)
w.Header().Set("AtEnd1", "value 1")
io.WriteString(w, "This HTTP response has both headers before this text and trailers at the end.\n")
w.Header().Set("AtEnd2", "value 2")
w.Header().Set("AtEnd3", "value 3") // These will appear as trailers.})}type RoundTripper
RoundTripper是一个接口，表示执行单个HTTP事务的能力，获得给定请求的响应。
RoundTripper必须是安全的，以供多个goroutine同时使用。
type RoundTripper interface { // RoundTrip executes a single HTTP transaction, returning // a Response for the provided Request. // // RoundTrip should not attempt to interpret the response. In // particular, RoundTrip must return err == nil if it obtained // a response, regardless of the response's HTTP status code. // A non-nil err should be reserved for failure to obtain a // response. Similarly, RoundTrip should not attempt to // handle higher-level protocol details such as redirects, // authentication, or cookies. // // RoundTrip should not modify the request, except for // consuming and closing the Request's Body. // // RoundTrip must always close the body, including on errors, // but depending on the implementation may do so in a separate // goroutine even after RoundTrip returns. This means that // callers wanting to reuse the body for subsequent requests // must arrange to wait for the Close call before doing so. // // The Request's URL and Header fields must be initialized. RoundTrip(*Request) (*Response, error)}DefaultTransport是Transport的默认实现，由DefaultClient使用。它根据需要建立网络连接，并将它们缓存以供随后的调用重用。它按照$ HTTP_PROXY和$ NO_PROXY（或$ http_proxy和$ no_proxy）环境变量的指示使用HTTP代理。
var DefaultTransport RoundTripper = &Transport{
Proxy: ProxyFromEnvironment,
DialContext: (&net.Dialer{
Timeout: 30 * time.Second,
KeepAlive: 30 * time.Second,
DualStack: true, }).DialContext,
MaxIdleConns: 100,
IdleConnTimeout: 90 * time.Second,
TLSHandshakeTimeout: 10 * time.Second,
ExpectContinueTimeout: 1 * time.Second,}func NewFileTransport
func NewFileTransport(fs FileSystem) RoundTripper
NewFileTransport返回一个新的RoundTripper，为所提供的FileSystem提供服务。返回的RoundTripper会忽略其传入请求中的URL主机以及请求的大多数其他属性。
NewFileTransport的典型用例是使用Transport注册“文件”协议，如下所示：
t := &http.Transport{}t.RegisterProtocol("file", http.NewFileTransport(http.Dir("/")))c := &http.Client{Transport: t}res, err := c.Get("file:///etc/passwd")...type ServeMux
ServeMux是一个HTTP请求多路复用器。它将每个传入请求的URL与注册模式列表进行匹配，并调用与该URL最匹配的模式的处理程序。
模式命名固定的，根源化的路径，如“/favicon.ico”，或根源子树，如“/images/”（注意尾部斜线）。较长的模式优先于较短的模式，因此，如果有处理程序注册了“/images/”和“/images / thumbnails/”，后一个处理程序将被调用以“/images/thumbnails/”开头的路径，前者将接收“/images/”子树中任何其他路径的请求。
请注意，由于以斜杠结尾的模式命名了一个有根的子树，因此模式“/”会匹配所有未被其他已注册模式匹配的路径，而不仅仅是具有Path ==“/”的URL。
如果一个子树已经注册并且接收到一个请求，并且命名了子树根而没有结尾的斜杠，ServeMux会将该请求重定向到子树根（添加尾部斜线）。此行为可以通过单独注册路径而不使用结尾斜杠来覆盖。例如，注册“/images/”会导致ServeMux将“/images”的请求重定向到“/images/”，除非单独注册了“/images”。
模式可以有选择地以主机名开头，只限制与主机上的URL匹配。特定于主机的模式优先于一般模式，因此处理程序可能会注册两种模式“/codesearch”和“codesearch.google.com/”，而不会接管“ http://www.google.com/”的请求”。
ServeMux还负责清理URL请求路径，重定向任何包含的请求。或..元素或重复的斜杠到一个等效的，更干净的URL。
type ServeMux struct { // contains filtered or unexported fields}func NewServeMux
func NewServeMux() *ServeMux
NewServeMux分配并返回一个新的ServeMux。
func (*ServeMux) Handle
func (mux *ServeMux) Handle(pattern string, handler Handler)
Handle为给定模式注册处理程序。如果处理程序已经存在模式，则处理恐慌。
示例
代码：
mux := http.NewServeMux()mux.Handle("/api/", apiHandler{})mux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) { // The "/" pattern matches everything, so we need to check // that we're at the root here. if req.URL.Path != "/" {
http.NotFound(w, req) return }
fmt.Fprintf(w, "Welcome to the home page!")})func (*ServeMux) HandleFunc
func (mux *ServeMux) HandleFunc(pattern string, handler func(ResponseWriter, *Request))
HandleFunc为给定模式注册处理函数。
func (*ServeMux) Handler
func (mux *ServeMux) Handler(r *Request) (h Handler, pattern string)
Handler返回用于给定请求的处理程序，请参阅r.Method，r.Host和r.URL.Path。它总是返回一个非零处理程序。如果路径不是其规范形式，则处理程序将是一个内部生成的处理程序，该处理程序将重定向到规范路径。如果主机包含端口，则在匹配处理程序时将忽略该端口。
CONNECT请求的路径和主机未改变。
处理程序还返回匹配请求的注册模式，或者在内部生成的重定向的情况下，返回跟随重定向后匹配的模式。
如果没有适用于请求的注册处理程序，则Handler返回“未找到页面”处理程序和空白模式。
func (*ServeMux) ServeHTTP
func (mux *ServeMux) ServeHTTP(w ResponseWriter, r *Request)
ServeHTTP将请求分派给其模式与请求URL最匹配的处理程序。
type Server
服务器定义运行HTTP服务器的参数。服务器的零值是有效的配置。
type Server struct {
Addr string // TCP address to listen on, ":http" if empty
Handler Handler // handler to invoke, http.DefaultServeMux if nil
TLSConfig *tls.Config // optional TLS config, used by ServeTLS and ListenAndServeTLS // ReadTimeout is the maximum duration for reading the entire // request, including the body. // // Because ReadTimeout does not let Handlers make per-request // decisions on each request body's acceptable deadline or // upload rate, most users will prefer to use // ReadHeaderTimeout. It is valid to use them both.
ReadTimeout time.Duration // ReadHeaderTimeout is the amount of time allowed to read // request headers. The connection's read deadline is reset // after reading the headers and the Handler can decide what // is considered too slow for the body.
ReadHeaderTimeout time.Duration // WriteTimeout is the maximum duration before timing out // writes of the response. It is reset whenever a new // request's header is read. Like ReadTimeout, it does not // let Handlers make decisions on a per-request basis.
WriteTimeout time.Duration // IdleTimeout is the maximum amount of time to wait for the // next request when keep-alives are enabled. If IdleTimeout // is zero, the value of ReadTimeout is used. If both are // zero, ReadHeaderTimeout is used.
IdleTimeout time.Duration // MaxHeaderBytes controls the maximum number of bytes the // server will read parsing the request header's keys and // values, including the request line. It does not limit the // size of the request body. // If zero, DefaultMaxHeaderBytes is used.
MaxHeaderBytes int // TLSNextProto optionally specifies a function to take over // ownership of the provided TLS connection when an NPN/ALPN // protocol upgrade has occurred. The map key is the protocol // name negotiated. The Handler argument should be used to // handle HTTP requests and will initialize the Request's TLS // and RemoteAddr if not already set. The connection is // automatically closed when the function returns. // If TLSNextProto is not nil, HTTP/2 support is not enabled // automatically.
TLSNextProto map[string]func(*Server, *tls.Conn, Handler) // ConnState specifies an optional callback function that is // called when a client connection changes state. See the // ConnState type and associated constants for details.
ConnState func(net.Conn, ConnState) // ErrorLog specifies an optional logger for errors accepting // connections and unexpected behavior from handlers. // If nil, logging goes to os.Stderr via the log package's // standard logger.
ErrorLog *log.Logger // contains filtered or unexported fields}func (*Server) Close
func (srv *Server) Close() error
立即关闭关闭状态StateNew，StateActive或StateIdle中的所有活动net.Listeners和任何连接。要正常关机，请使用关机。
关闭不会尝试关闭（甚至不知道）任何被劫持的连接，例如WebSockets。
Close返回关闭服务器底层侦听器返回的任何错误。
func (*Server) ListenAndServe
func (srv *Server) ListenAndServe() error
ListenAndServe监听TCP网络地址srv.Addr，然后调用Serve处理传入连接上的请求。接受的连接被配置为启用TCP保持活动。如果srv.Addr为空，则使用“:http”。ListenAndServe总是返回一个非零错误。
func (*Server) ListenAndServeTLS
func (srv *Server) ListenAndServeTLS(certFile, keyFile string) error
ListenAndServeTLS侦听TCP网络地址srv.Addr，然后调用Serve处理传入TLS连接上的请求。接受的连接被配置为启用TCP保持活动。
如果服务器的TLSConfig.Certificates和TLSConfig.GetCertificate都不填充，则必须提供包含服务器的证书和匹配私钥的文件名。如果证书由证书颁发机构签署，则certFile应该是服务器证书，任何中间器和CA证书的串联。
如果srv.Addr为空，则使用“:https”。
ListenAndServeTLS总是返回一个非零错误。
func (*Server) RegisterOnShutdown
func (srv *Server) RegisterOnShutdown(f func())
RegisterOnShutdown注册一个函数来调用Shutdown。这可以用于正常关闭经过NPN/ALPN协议升级或已被劫持的连接。此功能应启动特定于协议的正常关机，但不应等待关机完成。
func (*Server) Serve
func (srv *Server) Serve(l net.Listener) error
Serve接受Listener l上的传入连接，为每个服务器创建一个新的服务程序。服务程序读取请求，然后调用srv.Handler来回复它们。
对于HTTP/2支持，在调用Serve之前，应将srv.TLSConfig初始化为提供的侦听器的TLS配置。如果srv.TLSConfig非零，并且在Config.NextProtos中不包含字符串“h2”，则不启用HTTP/2支持。
始终返回非零错误。关机或关闭后，返回的错误是ErrServerClosed。
func (*Server) ServeTLS
func (srv *Server) ServeTLS(l net.Listener, certFile, keyFile string) error
ServeTLS接受Listener l上的传入连接，为每个连接创建一个新的服务例程。服务程序读取请求，然后调用srv.Handler来回复它们。
此外，如果服务器的TLSConfig.Certificates和TLSConfig.GetCertificate都未被填充，则必须提供包含服务器的证书和匹配私钥的文件。如果证书由证书颁发机构签署，则certFile应该是服务器的串联证书，任何中间件和CA的证书。
对于HTTP/2支持，在调用Serve之前，应将srv.TLSConfig初始化为提供的侦听器的TLS配置。如果srv.TLSConfig非零，并且在Config.NextProtos中不包含字符串“h2”，则不启用HTTP/2支持。
ServeTLS总是返回一个非零错误。关机或关闭后，返回的错误是ErrServerClosed。
func (*Server) SetKeepAlivesEnabled
func (srv *Server) SetKeepAlivesEnabled(v bool)
SetKeepAlivesEnabled控制是否启用HTTP保持活动。默认情况下，保持活动状态始终处于启用状态。在关闭过程中，只有非常资源受限的环境或服务器才能禁用它们。
func (*Server) Shutdown
func (srv *Server) Shutdown(ctx context.Context) error
关机正常关闭服务器而不中断任何活动连接。首先关闭所有打开的监听程序，然后关闭所有空闲连接，然后无限期地等待连接返回到空闲状态然后关闭。如果提供的上下文在关闭完成之前到期，Shutdown将返回上下文的错误，否则返回关闭服务器的底层侦听器返回的任何错误。
当调用Shutdown时，Serve，ListenAndServe和ListenAndServeTLS立即返回ErrServerClosed。确保程序不会退出，而是等待Shutdown返回。
关机不会尝试关闭或等待被劫持的连接，如WebSockets。如果需要，Shutdown的调用者应该分别通知关闭的这种长期连接并等待它们关闭。
type Transport
Transport是RoundTripper的一个实现，它支持HTTP，HTTPS和HTTP代理（对于使用CONNECT的HTTP或HTTPS）。
默认情况下，传输缓存连接以供将来重新使用。访问多台主机时可能会留下许多开放连接。可以使用传输的CloseIdleConnections方法和MaxIdleConnsPerHost和DisableKeepAlives字段管理此行为。
运输应该重用，而不是根据需要创建。运输对于多个goroutines并发使用是安全的。
传输是用于发出HTTP和HTTPS请求的低级原语。对于高级功能（如Cookie和重定向），请参阅客户端。
Transport对于HTTP URL使用HTTP/1.1，对于HTTPS URL使用HTTP/1.1或HTTP/2，具体取决于服务器是否支持HTTP/2以及如何配置Transport。DefaultTransport支持HTTP/2。要在传输上明确启用HTTP/2，请使用golang.org/x/net/http2并调用ConfigureTransport。有关HTTP/2的更多信息，请参阅软件包文档。
type Transport struct { // Proxy specifies a function to return a proxy for a given // Request. If the function returns a non-nil error, the // request is aborted with the provided error. // // The proxy type is determined by the URL scheme. "http" // and "socks5" are supported. If the scheme is empty, // "http" is assumed. // // If Proxy is nil or returns a nil *URL, no proxy is used.
Proxy func(*Request) (*url.URL, error) // DialContext specifies the dial function for creating unencrypted TCP connections. // If DialContext is nil (and the deprecated Dial below is also nil), // then the transport dials using package net.
DialContext func(ctx context.Context, network, addr string) (net.Conn, error) // Dial specifies the dial function for creating unencrypted TCP connections. // // Deprecated: Use DialContext instead, which allows the transport // to cancel dials as soon as they are no longer needed. // If both are set, DialContext takes priority.
Dial func(network, addr string) (net.Conn, error) // DialTLS specifies an optional dial function for creating // TLS connections for non-proxied HTTPS requests. // // If DialTLS is nil, Dial and TLSClientConfig are used. // // If DialTLS is set, the Dial hook is not used for HTTPS // requests and the TLSClientConfig and TLSHandshakeTimeout // are ignored. The returned net.Conn is assumed to already be // past the TLS handshake.
DialTLS func(network, addr string) (net.Conn, error) // TLSClientConfig specifies the TLS configuration to use with // tls.Client. // If nil, the default configuration is used. // If non-nil, HTTP/2 support may not be enabled by default.
TLSClientConfig *tls.Config // TLSHandshakeTimeout specifies the maximum amount of time waiting to // wait for a TLS handshake. Zero means no timeout.
TLSHandshakeTimeout time.Duration // DisableKeepAlives, if true, prevents re-use of TCP connections // between different HTTP requests.
DisableKeepAlives bool // DisableCompression, if true, prevents the Transport from // requesting compression with an "Accept-Encoding: gzip" // request header when the Request contains no existing // Accept-Encoding value. If the Transport requests gzip on // its own and gets a gzipped response, it's transparently // decoded in the Response.Body. However, if the user // explicitly requested gzip it is not automatically // uncompressed.
DisableCompression bool // MaxIdleConns controls the maximum number of idle (keep-alive) // connections across all hosts. Zero means no limit.
MaxIdleConns int // MaxIdleConnsPerHost, if non-zero, controls the maximum idle // (keep-alive) connections to keep per-host. If zero, // DefaultMaxIdleConnsPerHost is used.
MaxIdleConnsPerHost int // IdleConnTimeout is the maximum amount of time an idle // (keep-alive) connection will remain idle before closing // itself. // Zero means no limit.
IdleConnTimeout time.Duration // ResponseHeaderTimeout, if non-zero, specifies the amount of // time to wait for a server's response headers after fully // writing the request (including its body, if any). This // time does not include the time to read the response body.
ResponseHeaderTimeout time.Duration // ExpectContinueTimeout, if non-zero, specifies the amount of // time to wait for a server's first response headers after fully // writing the request headers if the request has an // "Expect: 100-continue" header. Zero means no timeout and // causes the body to be sent immediately, without // waiting for the server to approve. // This time does not include the time to send the request header.
ExpectContinueTimeout time.Duration // TLSNextProto specifies how the Transport switches to an // alternate protocol (such as HTTP/2) after a TLS NPN/ALPN // protocol negotiation. If Transport dials an TLS connection // with a non-empty protocol name and TLSNextProto contains a // map entry for that key (such as "h2"), then the func is // called with the request's authority (such as "example.com" // or "example.com:1234") and the TLS connection. The function // must return a RoundTripper that then handles the request. // If TLSNextProto is not nil, HTTP/2 support is not enabled // automatically.
TLSNextProto map[string]func(authority string, c *tls.Conn) RoundTripper // ProxyConnectHeader optionally specifies headers to send to // proxies during CONNECT requests.
ProxyConnectHeader Header // MaxResponseHeaderBytes specifies a limit on how many // response bytes are allowed in the server's response // header. // // Zero means to use a default limit.
MaxResponseHeaderBytes int64 // contains filtered or unexported fields}func (*Transport) CancelRequest
func (t *Transport) CancelRequest(req *Request)
CancelRequest通过关闭其连接来取消正在进行的请求。只有在RoundTrip返回后才能调用CancelRequest。
已弃用：使用Request.WithContext来创建具有可取消上下文的请求。CancelRequest无法取消HTTP/2请求。
func (*Transport) CloseIdleConnections
func (t *Transport) CloseIdleConnections()
CloseIdleConnections关闭以前连接的所有连接，但是现在处于“保持活动”状态。它不会中断当前正在使用的任何连接。
func (*Transport) RegisterProtocol
func (t *Transport) RegisterProtocol(scheme string, rt RoundTripper)
RegisterProtocol用方案注册一个新的协议。运输将使用给定的方案将请求传递给rt。模拟HTTP请求语义是rt的责任。
其他软件包可以使用RegisterProtocol来提供“ftp”或“file”等协议方案的实现。
如果rt.RoundTrip返回ErrSkipAltProtocol，Transport将为该请求处理RoundTrip本身，就好像该协议未注册一样。
func (*Transport) RoundTrip
func (t *Transport) RoundTrip(req *Request) (*Response, error)
RoundTrip实现RoundTripper接口。
对于更高级别的HTTP客户端支持（如处理Cookie和重定向），请参阅获取，发布和客户端类型。
子目录
Name | Synopsis |
|---|---|
cgi | cgi包实现了RFC 3875中规定的CGI（通用网关接口） |
cookiejar | 包cookiejar实现了符合内存RFC 6265的http.CookieJar。 |
fcgi | fcgi包实现FastCGI协议。 |
httptest | httptest包提供了用于HTTP测试的实用程序。 |
httptrace | 包httptrace提供跟踪HTTP客户端请求中的事件的机制。 |
httputil | 软件包httputil提供HTTP实用程序功能，补充了net/http软件包中较常见的功能。 |
pprof | 软件包pprof通过其HTTP服务器运行时分析数据以pprof可视化工具预期的格式提供服务。 |