พื้นฐานของ HTTP Server ของ package net/http

type Server struct {
    // Addr optionally specifies the TCP address for the server to listen on,
    // in the form "host:port". If empty, ":http" (port 80) is used.
    // The service names are defined in RFC 6335 and assigned by IANA.
    // See net.Dial for details of the address format.
    Addr string

    Handler Handler // handler to invoke, http.DefaultServeMux if nil

    // TLSConfig optionally provides a TLS configuration for use
    // by ServeTLS and ListenAndServeTLS. Note that this value is
    // cloned by ServeTLS and ListenAndServeTLS, so it's not
    // possible to modify the configuration with methods like
    // tls.Config.SetSessionTicketKeys. To use
    // SetSessionTicketKeys, use Server.Serve with a TLS Listener
    // instead.
    TLSConfig *tls.Config

    // 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. If ReadHeaderTimeout
    // is zero, the value of ReadTimeout is used. If both are
    // zero, there is no timeout.
    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, there is no timeout.
    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 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, unexpected behavior from handlers, and
    // underlying FileSystem errors.
    // If nil, logging is done via the log package's standard logger.
    ErrorLog *log.Logger

    // BaseContext optionally specifies a function that returns
    // the base context for incoming requests on this server.
    // The provided Listener is the specific Listener that's
    // about to start accepting requests.
    // If BaseContext is nil, the default is context.Background().
    // If non-nil, it must return a non-nil context.
    BaseContext func(net.Listener) context.Context

    // ConnContext optionally specifies a function that modifies
    // the context used for a new connection c. The provided ctx
    // is derived from the base context and has a ServerContextKey
    // value.
    ConnContext func(ctx context.Context, c net.Conn) context.Context
    // contains filtered or unexported fields
}

type Handler interface {
    ServeHTTP(ResponseWriter, *Request)
}

package main

import (
    "log"
    "net/http"
)

type handler struct{}

func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    w.Write([]byte("Hello, World\n"))
}

func main() {
    server := http.Server{
        Addr:    ":8000",
        Handler: &handler{},
    }
    err := server.ListenAndServe()
    if err != nil {
        log.Fatal(err)
    }
}

package main

import (
    "log"
    "net/http"
)

func main() {
    mux := http.NewServeMux()
    mux.HandleFunc("/hello", func(w http.ResponseWriter, r *http.Request) {
        w.Write([]byte("Hello, World\n"))
    })
    server := http.Server{
        Addr:    ":8000",
        Handler: mux,
    }
    err := server.ListenAndServe()
    if err != nil {
        log.Fatal(err)
    }
}

// HandleFunc registers the handler function for the given pattern.
func (mux *ServeMux) HandleFunc(pattern string, handler func(ResponseWriter, *Request)) {
    if handler == nil {
        panic("http: nil handler")
    }
    mux.Handle(pattern, HandlerFunc(handler))
}

// The HandlerFunc type is an adapter to allow the use of
// ordinary functions as HTTP handlers. If f is a function
// with the appropriate signature, HandlerFunc(f) is a
// Handler that calls f.
type HandlerFunc func(ResponseWriter, *Request)

// ServeHTTP calls f(w, r).
func (f HandlerFunc) ServeHTTP(w ResponseWriter, r *Request) {
    f(w, r)
}