golang实现正向代理http_proxy和https_proxy

package mainimport ("bytes""fmt""io""log""net""net/url""strings"
)func main() {// tcp 连接，监听 8080 端口l, err := net.Listen("tcp", ":8080")if err != nil {log.Panic(err)}// 死循环，每当遇到连接时，调用 handlefor {client, err := l.Accept()if err != nil {log.Panic(err)}go handle(client)}
}func handle(client net.Conn) {if client == nil {return}defer client.Close()log.Printf("remote addr: %v\n", client.RemoteAddr())// 用来存放客户端数据的缓冲区var b [1024]byte//从客户端获取数据n, err := client.Read(b[:])if err != nil {log.Println(err)return}var method, URL, address string// 从客户端数据读入 method，urlfmt.Sscanf(string(b[:bytes.IndexByte(b[:], '\n')]), "%s%s", &method, &URL)hostPortURL, err := url.Parse(URL)if err != nil {log.Println(err)