golang网络编程例程

今天药忘吃喽~ 2023-02-16 01:50 32阅读 0赞

### 文章目录 ###

*   *   *  1. TCP Server
         *  2. TCP Client
         *  3. UDP Server
         *  4. UDP Client

### 1. TCP Server ###

func startTcpServer() { 
      listener, err := net.Listen("tcp", "127.0.0.1:9003")
      if err != nil { 
        panic(err)
      }
      defer listener.Close()
      for { 
        conn, err := listener.Accept()
        if err != nil { 
          panic(err)
        }
        // go语言闭包函数对外部变量是以引用的方式引用，所以这里用函数传递conn
        go func(conn net.Conn) { 
          for { 
            buf := make([]byte, 1024)
            n, err := conn.Read(buf)
            if err != nil { 
              fmt.Println(err)
              break
            }
            msg := string(buf[:n])
            fmt.Println(conn.RemoteAddr(), ":", msg)
            if msg == "quit" { 
              conn.Write([]byte("Bye!"))
              conn.Close()
              break
            } else { 
              conn.Write([]byte("OK"))
            }
          }
        }(conn)
      }
    }

### 2. TCP Client ###

func startTcpClient() { 
      conn, err := net.Dial("tcp", "127.0.0.1:9003")
      if err != nil { 
        panic(err)
      }
      defer conn.Close()
      reader := bufio.NewReader(os.Stdin)
      for { 
        data, _, _ := reader.ReadLine()
        n, err := conn.Write(data)
        if err != nil { 
          fmt.Println(err)
          break
        }
        buf := make([]byte, 1024)
        n, err = conn.Read(buf)
        if err != nil { 
          fmt.Println(err)
          break
        }
        fmt.Println("Rev:", string(buf[:n]))
        if string(data) == "quit" { 
          break
        }
      }
    }

### 3. UDP Server ###

func startUdpServer() { 
      addr, err := net.ResolveUDPAddr("udp", "127.0.0.1:9003")
      if err != nil { 
        panic(err)
      }
      conn, err := net.ListenUDP("udp", addr)
      if err != nil { 
        panic(err)
      }
      defer conn.Close()
      buf := make([]byte, 1024)
      for { 
        // UDP面向无连接的通信，UDP Server接收报文。
        n, remoteAddr, err := conn.ReadFromUDP(buf)
        if err != nil { 
          fmt.Println(err)
          break
        }
        fmt.Println(remoteAddr, ": ", string(buf[:n]))
        conn.WriteToUDP([]byte("OK"), remoteAddr)
      }
    }

### 4. UDP Client ###

func startUdpClient() { 
      conn, err := net.Dial("udp", "127.0.0.1:9003")
      if err != nil { 
        panic(err)
      }
      defer conn.Close()
      reader := bufio.NewReader(os.Stdin)
      for { 
        data, _, _ := reader.ReadLine()
        n, err := conn.Write(data)
        if err != nil { 
          fmt.Println(err)
          break
        }
        buf := make([]byte, 1024)
        n, err = conn.Read(buf)
        if err != nil { 
          fmt.Println(err)
          break
        }
        fmt.Println("Rev:", string(buf[:n]))
        if string(data) == "quit" { 
          break
        }
      }
    }