net/http/client.go

135 lines
2.6 KiB
Go

package http
import (
"bufio"
"crypto/tls"
"errors"
"fmt"
"io"
"strconv"
"strings"
)
var (
CRLF = []byte("\r\n")
SP = []byte(" ")
)
func Do(method string, url string, headers []*Header) (*Response, error) {
url = strings.TrimPrefix(url, "http://")
url = strings.TrimPrefix(url, "https://")
path := "/"
arr := strings.Split(url, "/")
if len(arr) == 2 {
path = arr[1]
}
if !strings.HasPrefix(path, "/") {
path = "/" + path
}
connectPath := arr[0]
// conn, err := net.Dial("tcp", connectPath)
conn, err := tls.Dial("tcp", connectPath, nil)
if err != nil {
return nil, errors.New("connect " + connectPath)
}
defer conn.Close()
WriteRequest(conn, method, arr[0], path, "HTTP/1.0", headers)
return ReadResponse(conn)
}
func WriteRequest(
w io.Writer,
method string,
host string,
path string,
httpVersion string,
headers []*Header,
) {
io.WriteString(w, method)
w.Write(SP)
io.WriteString(w, path)
w.Write(SP)
io.WriteString(w, httpVersion)
w.Write(CRLF)
for _, header := range headers {
WriteHeader(w, header.Name, header.Value)
}
// headers end
w.Write(CRLF)
// todo: body
}
func WriteHeader(w io.Writer, name string, value string) {
fmt.Fprintf(w, "%s:%s", name, value)
w.Write(CRLF)
}
func ReadResponse(r io.Reader) (*Response, error) {
b := bufio.NewReader(r)
if _, err := b.ReadString(' '); err != nil {
return nil, errors.New("read httpVersion")
}
statusCodeStr, err := b.ReadString(' ')
if err != nil {
return nil, errors.New("read statusCode")
}
if _, err := b.ReadString('\r'); err != nil {
return nil, errors.New("read statusName")
}
if _, err := b.ReadString('\n'); err != nil {
return nil, errors.New("read LF")
}
statusCode, err := strconv.Atoi(statusCodeStr[:len(statusCodeStr)-1])
if err != nil {
return nil, errors.New("read statusCode")
}
headerStr := ""
contentLengthStr := ""
headers := []*Header{}
for {
headerStr, err = b.ReadString('\n')
if err != nil {
return nil, errors.New("read header")
}
if headerStr == "\r\n" {
break
}
arr := strings.Split(headerStr, ": ")
value := strings.TrimSpace(arr[1])
header := &Header{Name: arr[0], Value: value}
if header.Name == "Content-Length" {
contentLengthStr = header.Value
}
headers = append(headers, header)
}
length, err := strconv.Atoi(contentLengthStr)
if err != nil {
return nil, errors.New("read Content-Length")
}
body := make([]byte, 0, length)
for i := 0; i < length; i++ {
r, err := b.ReadByte()
if err != nil {
return nil, errors.New("read body")
}
body = append(body, r)
}
return &Response{
StatusCode: statusCode,
Headers: headers,
Body: body,
}, nil
}