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("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"}})
The client must close the response body when finished with it:
resp, err := http.Get("http:example.com/") if err != nil { handle error } defer resp.Body.Close() body, err := io.ReadAll(resp.Body) ...
For control over HTTP client headers, redirect policy, and othersettings, create a Client:
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) ...
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("https:example.com")
Clients and Transports are safe for concurrent use by multiplegoroutines 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 acustom Server:
s := &http.Server{ Addr: ":8080", Handler: myHandler, ReadTimeout: 10 * time.Second, WriteTimeout: 10 * time.Second, MaxHeaderBytes: 1 << 20, } log.Fatal(s.ListenAndServe())
Starting with Go 1.6, the http package has transparent support for theHTTP/2 protocol when using HTTPS. Programs that must disable HTTP/2can do so by setting Transport.TLSNextProto (for clients) orServer.TLSNextProto (for servers) to a non-nil, emptymap. Alternatively, the following GODEBUG environment variables arecurrently 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 compatibilitypromise. Please report any issues before disabling HTTP/2support: https:golang.org/s/http2bug
The http package's Transport and Server both automatically enableHTTP/2 support for simple configurations. To enable HTTP/2 for morecomplex configurations, to use lower-level HTTP/2 features, or to usea newer version of Go's http2 package, import "golang.org/x/net/http2"directly and use its ConfigureTransport and/or ConfigureServerfunctions. Manually configuring HTTP/2 via the golang.org/x/net/http2package takes precedence over the net/http package's built-in HTTP/2support.