// A Request represents an HTTP request received by a server
// or to be sent by a client.
//
// The field semantics differ slightly between client and server
// usage. In addition to the notes on the fields below, see the
// documentation for Request.Write and RoundTripper.
type Request struct {
// Method specifies the HTTP method (GET, POST, PUT, etc.).
// For client requests, an empty string means GET.
//
// Go's HTTP client does not support sending a request with
// the CONNECT method. See the documentation on Transport for
// details.
Method string
// URL specifies either the URI being requested (for server
// requests) or the URL to access (for client requests).
//
// For server requests, the URL is parsed from the URI
// supplied on the Request-Line as stored in RequestURI. For
// most requests, fields other than Path and RawQuery will be
// empty. (See RFC 7230, Section 5.3)
//
// For client requests, the URL's Host specifies the server to
// connect to, while the Request's Host field optionally
// specifies the Host header value to send in the HTTP
// request.
URL *url.URL
// The protocol version for incoming server requests.
//
// For client requests, these fields are ignored. The HTTP
// client code always uses either HTTP/1.1 or HTTP/2.
// See the docs on Transport for details.
Proto string // "HTTP/1.0"
ProtoMajor int // 1
ProtoMinor int // 0
// Header contains the request header fields either received
// by the server or to be sent by the client.
//
// If a server received a request with header lines,
//
// Host: example.com
// accept-encoding: gzip, deflate
// Accept-Language: en-us
// fOO: Bar
// foo: two
//
// then
//
// Header = map[string][]string{
// "Accept-Encoding": {"gzip, deflate"},
// "Accept-Language": {"en-us"},
// "Foo": {"Bar", "two"},
// }
//
// For incoming requests, the Host header is promoted to the
// Request.Host field and removed from the Header map.
//
// HTTP defines that header names are case-insensitive. The
// request parser implements this by using CanonicalHeaderKey,
// making the first character and any characters following a
// hyphen uppercase and the rest lowercase.
//
// For client requests, certain headers such as Content-Length
// and Connection are automatically written when needed and
// values in Header may be ignored. See the documentation
// for the Request.Write method.
Header Header
// Body is the request's body.
//
// For client requests, a nil body means the request has no
// body, such as a GET request. The HTTP Client's Transport
// is responsible for calling the Close method.
//
// For server requests, the Request Body is always non-nil
// but will return EOF immediately when no body is present.
// The Server will close the request body. The ServeHTTP
// Handler does not need to.
Body io.ReadCloser
// GetBody defines an optional func to return a new copy of
// Body. It is used for client requests when a redirect requires
// reading the body more than once. Use of GetBody still
// requires setting Body.
//
// For server requests, it is unused.
GetBody func() (io.ReadCloser, error)
// ContentLength records the length of the associated content.
// The value -1 indicates that the length is unknown.
// Values >= 0 indicate that the given number of bytes may
// be read from Body.
//
// For client requests, a value of 0 with a non-nil Body is
// also treated as unknown.
ContentLength int64
// TransferEncoding lists the transfer encodings from outermost to
// innermost. An empty list denotes the "identity" encoding.
// TransferEncoding can usually be ignored; chunked encoding is
// automatically added and removed as necessary when sending and
// receiving requests.
TransferEncoding []string
// Close indicates whether to close the connection after
// replying to this request (for servers) or after sending this
// request and reading its response (for clients).
//
// For server requests, the HTTP server handles this automatically
// and this field is not needed by Handlers.
//
// For client requests, setting this field prevents re-use of
// TCP connections between requests to the same hosts, as if
// Transport.DisableKeepAlives were set.
Close bool
// For server requests, Host specifies the host on which the URL
// is sought. Per RFC 7230, section 5.4, this is either the value
// of the "Host" header or the host name given in the URL itself.
// It may be of the form "host:port". For international domain
// names, Host may be in Punycode or Unicode form. Use
// golang.org/x/net/idna to convert it to either format if
// needed.
// To prevent DNS rebinding attacks, server Handlers should
// validate that the Host header has a value for which the
// Handler considers itself authoritative. The included
// ServeMux supports patterns registered to particular host
// names and thus protects its registered Handlers.
//
// For client requests, Host optionally overrides the Host
// header to send. If empty, the Request.Write method uses
// the value of URL.Host. Host may contain an international
// domain name.
Host string
// Form contains the parsed form data, including both the URL
// field's query parameters and the PATCH, POST, or PUT form data.
// This field is only available after ParseForm is called.
// The HTTP client ignores Form and uses Body instead.
Form url.Values
// PostForm contains the parsed form data from PATCH, POST
// or PUT body parameters.
//
// This field is only available after ParseForm is called.
// The HTTP client ignores PostForm and uses Body instead.
PostForm url.Values
// MultipartForm is the parsed multipart form, including file uploads.
// This field is only available after ParseMultipartForm is called.
// The HTTP client ignores MultipartForm and uses Body instead.
MultipartForm *multipart.Form
// Trailer specifies additional headers that are sent after the request
// body.
//
// For server requests, the Trailer map initially contains only the
// trailer keys, with nil values. (The client declares which trailers it
// will later send.) While the handler is reading from Body, it must
// not reference Trailer. After reading from Body returns EOF, Trailer
// can be read again and will contain non-nil values, if they were sent
// by the client.
//
// For client requests, Trailer must be initialized to a map containing
// the trailer keys to later send. The values may be nil or their final
// values. The ContentLength must be 0 or -1, to send a chunked request.
// After the HTTP request is sent the map values can be updated while
// the request body is read. Once the body returns EOF, the caller must
// not mutate Trailer.
//
// Few HTTP clients, servers, or proxies support HTTP trailers.
Trailer Header
// RemoteAddr allows HTTP servers and other software to record
// the network address that sent the request, usually for
// logging. This field is not filled in by ReadRequest and
// has no defined format. The HTTP server in this package
// sets RemoteAddr to an "IP:port" address before invoking a
// handler.
// This field is ignored by the HTTP client.
RemoteAddr string
// RequestURI is the unmodified request-target of the
// Request-Line (RFC 7230, Section 3.1.1) as sent by the client
// to a server. Usually the URL field should be used instead.
// It is an error to set this field in an HTTP client request.
RequestURI string
// TLS allows HTTP servers and other software to record
// information about the TLS connection on which the request
// was received. This field is not filled in by ReadRequest.
// The HTTP server in this package sets the field for
// TLS-enabled connections before invoking a handler;
// otherwise it leaves the field nil.
// This field is ignored by the HTTP client.
TLS *tls.ConnectionState
// Cancel is an optional channel whose closure indicates that the client
// request should be regarded as canceled. Not all implementations of
// RoundTripper may support Cancel.
//
// For server requests, this field is not applicable.
//
// Deprecated: Set the Request's context with NewRequestWithContext
// instead. If a Request's Cancel field and context are both
// set, it is undefined whether Cancel is respected.
Cancel <-chan struct{}
// Response is the redirect response which caused this request
// to be created. This field is only populated during client
// redirects.
Response *Response
// ctx is either the client or server context. It should only
// be modified via copying the whole Request using WithContext.
// It is unexported to prevent people from using Context wrong
// and mutating the contexts held by callers of the same request.
ctx context.Context
}
scheme://[userinfo@]host/path[?query][#fragment]
scheme:opaque[?query][#fragment]
// A URL represents a parsed URL (technically, a URI reference).
//
// The general form represented is:
//
// [scheme:][//[userinfo@]host][/]path[?query][#fragment]
//
// URLs that do not start with a slash after the scheme are interpreted as:
//
// scheme:opaque[?query][#fragment]
//
// Note that the Path field is stored in decoded form: /%47%6f%2f becomes /Go/.
// A consequence is that it is impossible to tell which slashes in the Path were
// slashes in the raw URL and which were %2f. This distinction is rarely important,
// but when it is, the code should use RawPath, an optional field which only gets
// set if the default encoding is different from Path.
//
// URL's String method uses the EscapedPath method to obtain the path. See the
// EscapedPath method for more details.
type URL struct {
Scheme string
Opaque string // encoded opaque data
User *Userinfo // username and password information
Host string // host or host:port
Path string // path (relative paths may omit leading slash)
RawPath string // encoded path hint (see EscapedPath method)
ForceQuery bool // append a query ('?') even if RawQuery is empty
RawQuery string // encoded query values, without '?'
Fragment string // fragment for references, without '#'
}
// A Header represents the key-value pairs in an HTTP header.
//
// The keys should be in canonical form, as returned by
// CanonicalHeaderKey.
type Header map[string][]string
// Add adds the key, value pair to the header.
// It appends to any existing values associated with key.
// The key is case insensitive; it is canonicalized by
// CanonicalHeaderKey.
func (h Header) Add(key, value string) {
textproto.MIMEHeader(h).Add(key, value)
}
// Set sets the header entries associated with key to the
// single element value. It replaces any existing values
// associated with key. The key is case insensitive; it is
// canonicalized by textproto.CanonicalMIMEHeaderKey.
// To use non-canonical keys, assign to the map directly.
func (h Header) Set(key, value string) {
textproto.MIMEHeader(h).Set(key, value)
}
// Get gets the first value associated with the given key. If
// there are no values associated with the key, Get returns "".
// It is case insensitive; textproto.CanonicalMIMEHeaderKey is
// used to canonicalize the provided key. To access multiple
// values of a key, or to use non-canonical keys, access the
// map directly.
func (h Header) Get(key string) string {
return textproto.MIMEHeader(h).Get(key)
}
// Del deletes the values associated with key.
// The key is case insensitive; it is canonicalized by
// CanonicalHeaderKey.
func (h Header) Del(key string) {
textproto.MIMEHeader(h).Del(key)
}
// Write writes a header in wire format.
func (h Header) Write(w io.Writer) error {
return h.write(w, nil)
}
map[User-Agent:[Mozilla/5.0 (Windows NT 10.0; Win64; x64)
AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.62 Safari/537.36]
Accept:[text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,ima
ge/apng,*/*;q=0.8] Accept-Encoding:[gzip, deflate, br] Accept-Language:[zhCN,zh;q=0.9,en-US;q=0.8,en;q=0.7] Connection:[keep-alive] Upgrade-InsecureRequests:[1]]
// ReadCloser is the interface that groups the basic Read and Close methods.
type ReadCloser interface {
Reader
Closer
}
// Reader is the interface that wraps the basic Read method.
//
// Read reads up to len(p) bytes into p. It returns the number of bytes
// read (0 <= n <= len(p)) and any error encountered. Even if Read
// returns n < len(p), it may use all of p as scratch space during the call.
// If some data is available but not len(p) bytes, Read conventionally
// returns what is available instead of waiting for more.
//
// When Read encounters an error or end-of-file condition after
// successfully reading n > 0 bytes, it returns the number of
// bytes read. It may return the (non-nil) error from the same call
// or return the error (and n == 0) from a subsequent call.
// An instance of this general case is that a Reader returning
// a non-zero number of bytes at the end of the input stream may
// return either err == EOF or err == nil. The next Read should
// return 0, EOF.
//
// Callers should always process the n > 0 bytes returned before
// considering the error err. Doing so correctly handles I/O errors
// that happen after reading some bytes and also both of the
// allowed EOF behaviors.
//
// Implementations of Read are discouraged from returning a
// zero byte count with a nil error, except when len(p) == 0.
// Callers should treat a return of 0 and nil as indicating that
// nothing happened; in particular it does not indicate EOF.
//
// Implementations must not retain p.
type Reader interface {
Read(p []byte) (n int, err error)
}
// Closer is the interface that wraps the basic Close method.
//
// The behavior of Close after the first call is undefined.
// Specific implementations may document their own behavior.
type Closer interface {
Close() error
}
index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<form action="http://localhost:8080/getBody" method="POST">
user name:<input type="text" name="username" value="hanzong"><br/>
password:<input type="password" name="password" value="666666"><br/>
<input type="submit">
</form>
</body>
</html>
main.go
package main
import "fmt"
import "net/http"
func handler(w http.ResponseWriter, r *http.Request) {
length := r.ContentLength
body := make([]byte, length)
r.Body.Read(body)
fmt.Fprintln(w, "请求体中的内容是：", string(body))
}
func main() {
http.HandleFunc("/getBody", handler)
http.ListenAndServe(":8080", nil)
}
// Values maps a string key to a list of values.
// It is typically used for query parameters and form values.
// Unlike in the http.Header map, the keys in a Values map
// are case-sensitive.
type Values map[string][]string
// Get gets the first value associated with the given key.
// If there are no values associated with the key, Get returns
// the empty string. To access multiple values, use the map
// directly.
func (v Values) Get(key string) string {
if v == nil {
return ""
}
vs := v[key]
if len(vs) == 0 {
return ""
}
return vs[0]
}
// Set sets the key to value. It replaces any existing
// values.
func (v Values) Set(key, value string) {
v[key] = []string{value}
}
// Add adds the value to key. It appends to any existing
// values associated with key.
func (v Values) Add(key, value string) {
v[key] = append(v[key], value)
}
// Del deletes the values associated with key.
func (v Values) Del(key string) {
delete(v, key)
}
// Encode encodes the values into ``URL encoded'' form
// ("bar=baz&foo=quux") sorted by key.
func (v Values) Encode() string {
if v == nil {
return ""
}
var buf strings.Builder
keys := make([]string, 0, len(v))
for k := range v {
keys = append(keys, k)
}
sort.Strings(keys)
for _, k := range keys {
vs := v[k]
keyEscaped := QueryEscape(k)
for _, v := range vs {
if buf.Len() > 0 {
buf.WriteByte('&')
}
buf.WriteString(keyEscaped)
buf.WriteByte('=')
buf.WriteString(QueryEscape(v))
}
}
return buf.String()
}
如果请求URL和请求Form中的字段不一样，可以使用http.Request.PostForm获取请求Form中的值
package main
import "fmt"
import "net/http"
func handler(w http.ResponseWriter, r *http.Request) {
r.ParseForm()
fmt.Fprintln(w, "请求参数为：", r.Form)
}
func main() {
http.HandleFunc("/getBody", handler)
http.ListenAndServe(":8080", nil)
}
package main
import "fmt"
import "net/http"
func handler(w http.ResponseWriter, r *http.Request) {
r.ParseForm()
fmt.Fprintln(w, "请求参数为：", r.PostForm)
}
func main() {
http.HandleFunc("/getBody", handler)
http.ListenAndServe(":8080", nil)
}
如果Form中的enctype属性值为”multipart/form-data”，那么PostForm字段无法获取表单中的数据，需要使用MutipartForm字段 Form的enctype属性默认值是”application/x-www-form-urlencoded”，实现上传文件时需要设置为”multipart/form-data”
index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<form action="http://localhost:8080/getBody" method="POST" enctype="application/x-www-form-urlencoded">
user name:<input type="text" name="username" value="hanzong"><br/>
password:<input type="password" name="password" value="666666"><br/>
<input type="submit">
</form>
<form action="http://localhost:8080/upload" method="POST" enctype="multipart/form-data">
<input type="text" name="username" value="hanzong"><br/>
文件：<input type="file" name="photo"><br/>
<input type="submit">
</form>
</body>
</html>
main.go
package main
import "fmt"
import "net/http"
func handler(w http.ResponseWriter, r *http.Request) {
r.ParseMultipartForm(1000)
fmt.Fprintln(w, "请求参数为：", r.MultipartForm)
}
func main() {
http.HandleFunc("/upload", handler)
http.ListenAndServe(":8080", nil)
}
mime.multipart.Form
// Form is a parsed multipart form.
// Its File parts are stored either in memory or on disk,
// and are accessible via the *FileHeader's Open method.
// Its Value parts are stored as strings.
// Both are keyed by field name.
type Form struct {
Value map[string][]string
File map[string][]*FileHeader
}
mime.multipart.FileHeader
// A FileHeader describes a file part of a multipart request.
type FileHeader struct {
Filename string
Header textproto.MIMEHeader
Size int64
content []byte
tmpfile string
}
// Open opens and returns the FileHeader's associated File.
func (fh *FileHeader) Open() (File, error) {
if b := fh.content; b != nil {
r := io.NewSectionReader(bytes.NewReader(b), 0, int64(len(b)))
return sectionReadCloser{r}, nil
}
return os.Open(fh.tmpfile)
}
main.go
package main
import (
"fmt"
"io/ioutil"
"net/http"
)
func handler(w http.ResponseWriter, r *http.Request) {
r.ParseMultipartForm(1000)
// fmt.Fprintln(w, "请求参数为：", r.MultipartForm)
fileHeader := r.MultipartForm.File["photo"][0]
file, err := fileHeader.Open()
if err != nil {
fmt.Println(err)
return
}
data, err := ioutil.ReadAll(file)
if err != nil {
fmt.Println(err)
return
}
fmt.Fprintln(w, string(data))
}
func main() {
http.HandleFunc("/upload", handler)
http.ListenAndServe(":8080", nil)
}
如果只上传一个文件，可以使用http.Request.PostFile
main.go
package main
import (
"fmt"
"io/ioutil"
"net/http"
)
func handler(w http.ResponseWriter, r *http.Request) {
file, _, err := r.FormFile("photo")
if err != nil {
fmt.Println(err)
return
}
data, err := ioutil.ReadAll(file)
if err != nil {
fmt.Println(err)
return
}
fmt.Fprintln(w, string(data))
}
func main() {
http.HandleFunc("/upload", handler)
http.ListenAndServe(":8080", nil)
}
// A ResponseWriter interface is used by an HTTP handler to
// construct an HTTP response.
//
// A ResponseWriter may not be used after the Handler.ServeHTTP method
// has returned.
type ResponseWriter interface {
// Header returns the header map that will be sent by
// WriteHeader. The Header map also is the mechanism with which
// Handlers can set HTTP trailers.
//
// Changing the header map after a call to WriteHeader (or
// Write) has no effect unless the modified headers are
// trailers.
//
// There are two ways to set Trailers. The preferred way is to
// predeclare in the headers which trailers you will later
// send by setting the "Trailer" header to the names of the
// trailer keys which will come later. In this case, those
// keys of the Header map are treated as if they were
// trailers. See the example. The second way, for trailer
// keys not known to the Handler until after the first Write,
// is to prefix the Header map keys with the TrailerPrefix
// constant value. See TrailerPrefix.
//
// To suppress automatic response headers (such as "Date"), set
// their value to nil.
Header() Header
// Write writes the data to the connection as part of an HTTP reply.
//
// If WriteHeader has not yet been called, Write calls
// WriteHeader(http.StatusOK) before writing the data. If the Header
// does not contain a Content-Type line, Write adds a Content-Type set
// to the result of passing the initial 512 bytes of written data to
// DetectContentType. Additionally, if the total size of all written
// data is under a few KB and there are no Flush calls, the
// Content-Length header is added automatically.
//
// Depending on the HTTP protocol version and the client, calling
// Write or WriteHeader may prevent future reads on the
// Request.Body. For HTTP/1.x requests, handlers should read any
// needed request body data before writing the response. Once the
// headers have been flushed (due to either an explicit Flusher.Flush
// call or writing enough data to trigger a flush), the request body
// may be unavailable. For HTTP/2 requests, the Go HTTP server permits
// handlers to continue to read the request body while concurrently
// writing the response. However, such behavior may not be supported
// by all HTTP/2 clients. Handlers should read before writing if
// possible to maximize compatibility.
Write([]byte) (int, error)
// WriteHeader sends an HTTP response header with the provided
// status code.
//
// If WriteHeader is not called explicitly, the first call to Write
// will trigger an implicit WriteHeader(http.StatusOK).
// Thus explicit calls to WriteHeader are mainly used to
// send error codes.
//
// The provided code must be a valid HTTP 1xx-5xx status code.
// Only one header may be written. Go does not currently
// support sending user-defined 1xx informational headers,
// with the exception of 100-continue response header that the
// Server sends automatically when the Request.Body is read.
WriteHeader(statusCode int)
}
package main
import (
"net/http"
)
func handler(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("你的请求我已经收到"))
}
func main() {
http.HandleFunc("/", handler)
http.ListenAndServe(":8080", nil)
}
浏览器显示
你的请求我已经收到
响应报文内容
HTTP/1.1 200 OK
Date: Tue, 07 Jan 2020 13:08:11 GMT
Content-Length: 27
Content-Type: text/plain; charset=utf-8
package main
import (
"net/http"
)
func handler(w http.ResponseWriter, r *http.Request) {
html := `<html>
<head>
<title>网页title</title>
<meta charset="utf-8"/>
</head>
<body>
<h1>网页body</h1>
</body>
</html>`
w.Write([]byte(html))
}
func main() {
http.HandleFunc("/", handler)
http.ListenAndServe(":8080", nil)
}
package main
import (
"encoding/json"
"fmt"
"net/http"
)
type User struct {
ID int
UserName string
Password string
}
func handler(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
user := User{
ID: 1,
UserName: "admin",
Password: "123456",
}
json, err := json.Marshal(user)
if err != nil {
fmt.Println(err)
return
}
w.Write(json)
}
func main() {
http.HandleFunc("/", handler)
http.ListenAndServe(":8080", nil)
}
package main
import (
"net/http"
)
func handler(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Location", "https://www.baidu.com")
w.WriteHeader(302)
}
func main() {
http.HandleFunc("/", handler)
http.ListenAndServe(":8080", nil)
}
响应报文
HTTP/1.1 302 Found
Location: https://www.baidu.com
Date: Tue, 07 Jan 2020 13:25:59 GMT
Content-Length: 0