操作系统: CentOS 6.9_x64
go语言版本: 1.8.3
问题描述
现有一个tcp客户端程序,需定期从服务器取数据,但由于种种原因(网络不稳定等)需要自动重连。
测试服务器示例代码:
/* tcp server for test E-Mail : Mike_Zhang@live.com */ package main import ( "fmt"
"net"
"os"
"strings"
"time" ) func checkError(err error) { if err != nil { fmt.Println(err) os.Exit(1) } } func handleClient(conn net.Conn) { conn.SetReadDeadline(time.Now().Add(3 * time.Minute)) request := make([]byte,1024) defer conn.Close() for { recv_len,err := conn.Read(request) if err != nil { fmt.Println(err) break } if recv_len == 0 { break } recvData := strings.TrimSpace(string(request[:recv_len])) fmt.Println("recv_len : ",recv_len) fmt.Println("recv_data : " + recvData) daytime := time.Now().String() conn.Write([]byte(daytime + "\n")) request = make([]byte,1024) } } func main() { bindInfo := ":12345" tcpAddr,err := net.ResolveTCPAddr("tcp4",bindInfo) checkError(err) listener,err := net.ListenTCP("tcp",tcpAddr) checkError(err) for { cc,err := listener.Accept() if err != nil { continue } go handleClient(cc) } }
解决方案
/* tcp client with reconnect E-Mail : Mike_Zhang@live.com */ package main import ( "net"
"fmt"
"bufio"
"time" ) func doTask(conn net.Conn) { for { fmt.Fprintf(conn,"test msg\n") msg,err := bufio.NewReader(conn).ReadString('\n') if err != nil { fmt.Println("recv data error") break }else{ fmt.Println("recv msg : ",msg) } time.Sleep(1 * time.Second) } } func main() { hostInfo := "127.0.0.1:12345"
for { conn,err := net.Dial("tcp",hostInfo) fmt.Print("connect (",hostInfo) if err != nil { fmt.Println(") fail") }else{ fmt.Println(") ok") defer conn.Close() doTask(conn) } time.Sleep(3 * time.Second) } }
运行效果:
[root@local t1]# ./tcpClient1 connect (127.0.0.1:12345) ok recv msg : 2017-06-12 21:10:32.110977137 +0800 CST recv msg : 2017-06-12 21:10:33.111868746 +0800 CST recv data error connect (127.0.0.1:12345) fail connect (127.0.0.1:12345) fail connect (127.0.0.1:12345) ok recv msg : 2017-06-12 21:10:43.117203432 +0800 CST recv msg : 2017-06-12 21:10:44.11853427 +0800 CST
讨论
这里只是个简单的示例代码,实现了tcp自动重连。
好,就这些了,希望对你有帮助。
本文github地址:
https://github.com/mike-zhang/mikeBlogEssays/blob/master/2017/20170613_golang之tcp自动重连.rst
欢迎补充
有疑问加站长微信联系(非本文作者)