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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
Package http provides HTTP client and server implementations.
Get, Head, Post, and PostForm make HTTP (or HTTPS) requests:
resp, err := http.Get("")
resp, err := http.Post("", "image/jpeg", &buf)
resp, err := http.PostForm("",
url.Values{"key": {"Value"}, "id": {"123"}})
The client must close the response body when finished with it:
resp, err := http.Get("")
if err != nil {
// handle error
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
// ...
For control over HTTP client headers, redirect policy, and other
settings, create a Client:
client := &http.Client{
CheckRedirect: redirectPolicyFunc,
resp, err := client.Get("")
// ...
req, err := http.NewRequest("GET", "", nil)
// ...
req.Header.Add("If-None-Match", `W/"wyzzy"`)
resp, err := client.Do(req)
// ...
For control over proxies, TLS configuration, keep-alives,
compression, and other settings, create a Transport:
tr := &http.Transport{
MaxIdleConns: 10,
IdleConnTimeout: 30 * time.Second,
DisableCompression: true,
client := &http.Client{Transport: tr}
resp, err := client.Get("")
Clients and Transports are safe for concurrent use by multiple
goroutines and for efficiency should only be created once and re-used.
ListenAndServe starts an HTTP server with a given address and handler.
The handler is usually nil, which means to use DefaultServeMux.
Handle and HandleFunc add handlers to 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))
More control over the server's behavior is available by creating a
custom Server:
s := &http.Server{
Addr: ":8080",
Handler: myHandler,
ReadTimeout: 10 * time.Second,
WriteTimeout: 10 * time.Second,
MaxHeaderBytes: 1 << 20,
Starting with Go 1.6, the http package has transparent support for the
HTTP/2 protocol when using HTTPS. Programs that must disable HTTP/2
can do so by setting Transport.TLSNextProto (for clients) or
Server.TLSNextProto (for servers) to a non-nil, empty
map. Alternatively, the following GODEBUG environment variables are
currently supported:
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
The GODEBUG variables are not covered by Go's API compatibility
promise. Please report any issues before disabling HTTP/2
The http package's Transport and Server both automatically enable
HTTP/2 support for simple configurations. To enable HTTP/2 for more
complex configurations, to use lower-level HTTP/2 features, or to use
a newer version of Go's http2 package, import ""
directly and use its ConfigureTransport and/or ConfigureServer
functions. Manually configuring HTTP/2 via the
package takes precedence over the net/http package's built-in HTTP/2
package http