Go语言圣经–示例: 并发的Echo服务详解编程语言

原理：

1.io.Copy()方法
func Copy(dst Writer, src Reader) (written int64, err error)

2.net.Conn类型
type Conn interface {
Read(b []byte) (n int, err error)
Write(b []byte) (n int, err error)

}
一个类型如果拥有一个接口需要的所有方法，那么这个类型就实现了这个接口

3.io.Writer
type Writer interface {
Write(p []byte) (n int, err error)
}
4.io.Reader
type Reader interface {
Read(p []byte) (n int, err error)
}

升级版，每条连接一个goroutine,每个goroutine中分出多个输出goroutine

package main 

import ( 

 "bufio" 

 "fmt" 

 "log" 

 "net" 

 "strings" 

 "time" 

func main() { 

 listener, err := net.Listen("tcp", ":8040") 

 if err != nil { 

 log.Fatal(err) 

 for { 

 conn, err := listener.Accept() 

 if err != nil { 

 log.Print(err) // e.g., connection aborted 

 continue 

 go handleConn(conn) //新建goroutines处理连接 

func handleConn(c net.Conn) { 

 input := bufio.NewScanner(c) 

 for input.Scan() { 

 go echo(c, input.Text(), 1*time.Second) 

 // NOTE: ignoring potential errors from input.Err() 

 c.Close() 

func echo(c net.Conn, shout string, delay time.Duration) { 

 fmt.Fprintln(c, "/t", strings.ToUpper(shout)) 

 time.Sleep(delay) 

 fmt.Fprintln(c, "/t", shout) 

 time.Sleep(delay) 

 fmt.Fprintln(c, "/t", strings.ToLower(shout)) 

1.fmt.Fprintln()
func Fprintln(w io.Writer, a interface{}) (n int, err error)

2.bufio.NewScanner()
func NewScanner(r io.Reader) *Scanner
func (s *Scanner) Scan() bool
func (s *Scanner) Text() string

也用到了大量的7.3节 实现接口的条件

原创文章，作者：ItWorker，如若转载，请注明出处：https://blog.ytso.com/12531.html