doc.go

     1  // Copyright 2011 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  /*
     6  Package http provides HTTP client and server implementations.
     7  
     8  Get, Head, Post, and PostForm make HTTP (or HTTPS) requests:
     9  
    10  	resp, err := http.Get("http://example.com/")
    11  	...
    12  	resp, err := http.Post("http://example.com/upload", "image/jpeg", &buf)
    13  	...
    14  	resp, err := http.PostForm("http://example.com/form",
    15  		url.Values{"key": {"Value"}, "id": {"123"}})
    16  
    17  The client must close the response body when finished with it:
    18  
    19  	resp, err := http.Get("http://example.com/")
    20  	if err != nil {
    21  		// handle error
    22  	}
    23  	defer resp.Body.Close()
    24  	body, err := io.ReadAll(resp.Body)
    25  	// ...
    26  
    27  For control over HTTP client headers, redirect policy, and other
    28  settings, create a Client:
    29  
    30  	client := &http.Client{
    31  		CheckRedirect: redirectPolicyFunc,
    32  	}
    33  
    34  	resp, err := client.Get("http://example.com")
    35  	// ...
    36  
    37  	req, err := http.NewRequest("GET", "http://example.com", nil)
    38  	// ...
    39  	req.Header.Add("If-None-Match", `W/"wyzzy"`)
    40  	resp, err := client.Do(req)
    41  	// ...
    42  
    43  For control over proxies, TLS configuration, keep-alives,
    44  compression, and other settings, create a Transport:
    45  
    46  	tr := &http.Transport{
    47  		MaxIdleConns:       10,
    48  		IdleConnTimeout:    30 * time.Second,
    49  		DisableCompression: true,
    50  	}
    51  	client := &http.Client{Transport: tr}
    52  	resp, err := client.Get("https://example.com")
    53  
    54  Clients and Transports are safe for concurrent use by multiple
    55  goroutines and for efficiency should only be created once and re-used.
    56  
    57  ListenAndServe starts an HTTP server with a given address and handler.
    58  The handler is usually nil, which means to use DefaultServeMux.
    59  Handle and HandleFunc add handlers to DefaultServeMux:
    60  
    61  	http.Handle("/foo", fooHandler)
    62  
    63  	http.HandleFunc("/bar", func(w http.ResponseWriter, r *http.Request) {
    64  		fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path))
    65  	})
    66  
    67  	log.Fatal(http.ListenAndServe(":8080", nil))
    68  
    69  More control over the server's behavior is available by creating a
    70  custom Server:
    71  
    72  	s := &http.Server{
    73  		Addr:           ":8080",
    74  		Handler:        myHandler,
    75  		ReadTimeout:    10 * time.Second,
    76  		WriteTimeout:   10 * time.Second,
    77  		MaxHeaderBytes: 1 << 20,
    78  	}
    79  	log.Fatal(s.ListenAndServe())
    80  
    81  Starting with Go 1.6, the http package has transparent support for the
    82  HTTP/2 protocol when using HTTPS. Programs that must disable HTTP/2
    83  can do so by setting Transport.TLSNextProto (for clients) or
    84  Server.TLSNextProto (for servers) to a non-nil, empty
    85  map. Alternatively, the following GODEBUG environment variables are
    86  currently supported:
    87  
    88  	GODEBUG=http2client=0  # disable HTTP/2 client support
    89  	GODEBUG=http2server=0  # disable HTTP/2 server support
    90  	GODEBUG=http2debug=1   # enable verbose HTTP/2 debug logs
    91  	GODEBUG=http2debug=2   # ... even more verbose, with frame dumps
    92  
    93  The GODEBUG variables are not covered by Go's API compatibility
    94  promise. Please report any issues before disabling HTTP/2
    95  support: https://golang.org/s/http2bug
    96  
    97  The http package's Transport and Server both automatically enable
    98  HTTP/2 support for simple configurations. To enable HTTP/2 for more
    99  complex configurations, to use lower-level HTTP/2 features, or to use
   100  a newer version of Go's http2 package, import "golang.org/x/net/http2"
   101  directly and use its ConfigureTransport and/or ConfigureServer
   102  functions. Manually configuring HTTP/2 via the golang.org/x/net/http2
   103  package takes precedence over the net/http package's built-in HTTP/2
   104  support.
   105  
   106  */
   107  package http
   108
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