github.com/ltltlt/go-source-code@v0.0.0-20190830023027-95be009773aa/net/http/example_test.go (about)

     1  // Copyright 2012 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  package http_test
     6  
     7  import (
     8  	"context"
     9  	"fmt"
    10  	"io"
    11  	"io/ioutil"
    12  	"log"
    13  	"net/http"
    14  	"os"
    15  	"os/signal"
    16  )
    17  
    18  func ExampleHijacker() {
    19  	http.HandleFunc("/hijack", func(w http.ResponseWriter, r *http.Request) {
    20  		hj, ok := w.(http.Hijacker)
    21  		if !ok {
    22  			http.Error(w, "webserver doesn't support hijacking", http.StatusInternalServerError)
    23  			return
    24  		}
    25  		conn, bufrw, err := hj.Hijack()
    26  		if err != nil {
    27  			http.Error(w, err.Error(), http.StatusInternalServerError)
    28  			return
    29  		}
    30  		// Don't forget to close the connection:
    31  		defer conn.Close()
    32  		bufrw.WriteString("Now we're speaking raw TCP. Say hi: ")
    33  		bufrw.Flush()
    34  		s, err := bufrw.ReadString('\n')
    35  		if err != nil {
    36  			log.Printf("error reading string: %v", err)
    37  			return
    38  		}
    39  		fmt.Fprintf(bufrw, "You said: %q\nBye.\n", s)
    40  		bufrw.Flush()
    41  	})
    42  }
    43  
    44  func ExampleGet() {
    45  	res, err := http.Get("http://www.google.com/robots.txt")
    46  	if err != nil {
    47  		log.Fatal(err)
    48  	}
    49  	robots, err := ioutil.ReadAll(res.Body)
    50  	res.Body.Close()
    51  	if err != nil {
    52  		log.Fatal(err)
    53  	}
    54  	fmt.Printf("%s", robots)
    55  }
    56  
    57  func ExampleFileServer() {
    58  	// Simple static webserver:
    59  	log.Fatal(http.ListenAndServe(":8080", http.FileServer(http.Dir("/usr/share/doc"))))
    60  }
    61  
    62  func ExampleFileServer_stripPrefix() {
    63  	// To serve a directory on disk (/tmp) under an alternate URL
    64  	// path (/tmpfiles/), use StripPrefix to modify the request
    65  	// URL's path before the FileServer sees it:
    66  	http.Handle("/tmpfiles/", http.StripPrefix("/tmpfiles/", http.FileServer(http.Dir("/tmp"))))
    67  }
    68  
    69  func ExampleStripPrefix() {
    70  	// To serve a directory on disk (/tmp) under an alternate URL
    71  	// path (/tmpfiles/), use StripPrefix to modify the request
    72  	// URL's path before the FileServer sees it:
    73  	http.Handle("/tmpfiles/", http.StripPrefix("/tmpfiles/", http.FileServer(http.Dir("/tmp"))))
    74  }
    75  
    76  type apiHandler struct{}
    77  
    78  func (apiHandler) ServeHTTP(http.ResponseWriter, *http.Request) {}
    79  
    80  func ExampleServeMux_Handle() {
    81  	mux := http.NewServeMux()
    82  	mux.Handle("/api/", apiHandler{})
    83  	mux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
    84  		// The "/" pattern matches everything, so we need to check
    85  		// that we're at the root here.
    86  		if req.URL.Path != "/" {
    87  			http.NotFound(w, req)
    88  			return
    89  		}
    90  		fmt.Fprintf(w, "Welcome to the home page!")
    91  	})
    92  }
    93  
    94  // HTTP Trailers are a set of key/value pairs like headers that come
    95  // after the HTTP response, instead of before.
    96  func ExampleResponseWriter_trailers() {
    97  	mux := http.NewServeMux()
    98  	mux.HandleFunc("/sendstrailers", func(w http.ResponseWriter, req *http.Request) {
    99  		// Before any call to WriteHeader or Write, declare
   100  		// the trailers you will set during the HTTP
   101  		// response. These three headers are actually sent in
   102  		// the trailer.
   103  		w.Header().Set("Trailer", "AtEnd1, AtEnd2")
   104  		w.Header().Add("Trailer", "AtEnd3")
   105  
   106  		w.Header().Set("Content-Type", "text/plain; charset=utf-8") // normal header
   107  		w.WriteHeader(http.StatusOK)
   108  
   109  		w.Header().Set("AtEnd1", "value 1")
   110  		io.WriteString(w, "This HTTP response has both headers before this text and trailers at the end.\n")
   111  		w.Header().Set("AtEnd2", "value 2")
   112  		w.Header().Set("AtEnd3", "value 3") // These will appear as trailers.
   113  	})
   114  }
   115  
   116  func ExampleServer_Shutdown() {
   117  	var srv http.Server
   118  
   119  	idleConnsClosed := make(chan struct{})
   120  	go func() {
   121  		sigint := make(chan os.Signal, 1)
   122  		signal.Notify(sigint, os.Interrupt)
   123  		<-sigint
   124  
   125  		// We received an interrupt signal, shut down.
   126  		if err := srv.Shutdown(context.Background()); err != nil {
   127  			// Error from closing listeners, or context timeout:
   128  			log.Printf("HTTP server Shutdown: %v", err)
   129  		}
   130  		close(idleConnsClosed)
   131  	}()
   132  
   133  	if err := srv.ListenAndServe(); err != http.ErrServerClosed {
   134  		// Error starting or closing listener:
   135  		log.Printf("HTTP server ListenAndServe: %v", err)
   136  	}
   137  
   138  	<-idleConnsClosed
   139  }