tcp连接

服务器端

package main
import (
  "fmt"
  "net"
  "strings"
)
func  HandleConnect( conn net.Conn)  {
    defer conn.Close()
    addr:=conn.RemoteAddr()
    fmt.Println(addr,"客户端成功连接")
    buf:=make([]byte,4096)
    for {
      n,err:=conn.Read(buf)
      if "exit\n" == string(buf[:n]) ||  "exit\r\n" == string(buf[:n]){
        fmt.Println("客户端关闭连接")
        return
      }
      if n ==0 {
        fmt.Println("Client is close")
        return
      }
      if err != nil {
        fmt.Println("conn Read err",err)
        return
      }
      fmt.Println("服务器读到客户端数据:",string(buf[:n]))
      conn.Write([]byte(strings.ToUpper(string(buf[:n]))))
    }
}
func main(){
  listener,err:= net.Listen("tcp","127.0.0.1:9001")
  if err != nil {
    fmt.Println("net.listen is error")
    return
  }
  defer listener.Close()
  fmt.Println("服务器等待客户端连接...")
  for {
    conn,err:= listener.Accept()
    if err != nil {
      fmt.Println("accept is error") 
      return
    }
    go HandleConnect(conn)
  }
}

客户端

package main

import (
  "fmt"
  "net"
  "os"
)

func main(){
  conn,err:=net.Dial("tcp","127.0.0.1:9001")
  if err != nil {
    fmt.Println("connect server is error")
    return
  }
  defer conn.Close()

  go func(){
    str:=make([]byte,4096)
    for {
      n,err:=os.Stdin.Read(str)
      if n ==0 {
        fmt.Println("server is close")
        return
      }
      if err != nil {
        fmt.Println("os.Stdin is error")
        continue
      }
      conn.Write(str[:n])
    }
  }()
  //读取服务器
  buf:=make([]byte,4096)
  for {
    n,err:=conn.Read(buf)
    if n == 0 {
      fmt.Println("服务端关闭连接了...")
      return
    }
    if "exit\n" == string(buf[:n]) || "exit\r\n" == string(buf[:n]) {
      fmt.Println("客户端关闭连接")
      return
    }
    if err != nil {
      fmt.Println("os.buf is error")
      return
    }
    fmt.Println("客户端读到服务端数据：", string(buf[:n]))
  }
}

使用案例【tcp发送文件】------------------------------------------------

服务端

package main

import (
  "fmt"
  "io"
  "log"
  "net"
  "os"
)
func recvFile(conn net.Conn,fileName string){
  f,err:=os.Create(fileName)
  if err != nil {
    log.Println("Create File is error")
    return
  }
  defer f.Close()
  buf:=make([]byte,4096)
  for {
    n,_:=conn.Read(buf)
    if n==0 {
      fmt.Println("finsh")
      return
    }
    f.Write(buf[:n])
  }
}

func main(){
  listener,err:= net.Listen("tcp","127.0.0.1:8007")
  if err != nil {
    fmt.Println("net.Listen is error")
    return
  }
  defer listener.Close()
  conn,err:=listener.Accept()
  //获取文件名字
  bufName:=make([]byte,4096)
  n,err:=conn.Read(bufName)
  if err != nil {
    if err == io.EOF {
      fmt.Println("finish")
    }
    return
  }
  fileName:= string(bufName[:n])
  recvFile(conn,fileName)
}

客户端

package main

import (
  "fmt"
  "io"
  "log"
  "net"
  "os"
)
func readFile(conn net.Conn,path string){
  fd,_:=os.Open(path)
  buf:=make([]byte,4096)
  for {
    n,err:=fd.Read(buf)
    if err == io.EOF {
      fmt.Println("send file fiinish")
      return
    }
    conn.Write(buf[:n])
  }
  defer fd.Close()
}
func main(){
  lists:= os.Args
  if len(lists) != 2 {
    log.Println("params is errors")
    return
  }
  path:= lists[1]

  conn,err:=net.Dial("tcp","127.0.0.1:8007")
  if err != nil {
    fmt.Println("conn is erros")
    return
  }
  defer conn.Close()
  fileInfo,_:= os.Stat(path)
  fileName := fileInfo.Name()
  fmt.Println(fileName)
  conn.Write([]byte(fileName))//发送文件名字
  readFile(conn,path)
}