package main import (     "fmt"     "log"     "net"     "strconv" ) func handleConnection(conn net.Conn, talkChan map[int]chan string) {     //fmt.Printf("%p\n", talkChan)  //用以检查是否是传过来的指针     /*         定义当前用户的uid     */     var curUid int     var err error     /*         定义关闭通道     */     var closed = make(chan bool)     defer func() {         fmt.Println("defer do : conn closed")         conn.Close()         fmt.Printf("delete userid [%v] from talkChan", curUid)         delete(talkChan, curUid)     }()     /**      * 提示用户设置自己的uid， 如果没设置，则不朝下执行      */     for {         //提示客户端设置用户id         _, err = conn.Write([]byte("请设置用户uid"))         if err != nil {             return         }         data := make([]byte, 1024)         c, err := conn.Read(data)         if err != nil {             //closed <- true  //这样会阻塞 | 后面取closed的for循环，没有执行到。             return         }         sUid := string(data[0:c])         //转成int类型         uid, _ := strconv.Atoi(sUid)         if uid < 1 {             continue         }         curUid = uid         talkChan[uid] = make(chan string)         //fmt.Println(conn, "have set uid ", uid, "can talk")         _, err = conn.Write([]byte("have set uid "+sUid+" can talk"))         if err != nil {             return         }         break     }     fmt.Println("err 3")     //当前所有的连接     fmt.Println(talkChan)     //读取客户端传过来的数据     go func() {         for {             //不停的读客户端传过来的数据             data := make([]byte, 1024)             c, err := conn.Read(data)             if err != nil {                 fmt.Println("have no client write", err)                 closed <- true //这里可以使用 | 因为是用用的go 新开的线程去处理的。 |  即便chan阻塞，后面的也会执行去读 closed 这个chan             }             clientString := string(data[0:c])             //将客户端过来的数据，写到相应的chan里             if curUid == 3 {                 talkChan[4] <- clientString             } else {                 talkChan[3] <- clientString             }         }     }()     /*         从chan 里读出给这个客户端的数据 然后写到该客户端里     */     go func() {         for {             talkString := <-talkChan[curUid]             _, err = conn.Write([]byte(talkString))             if err != nil {                 closed <- true             }         }     }()     /*        检查是否已经关闭连接 如果关闭则推出该线程  去执行defer语句     */     for {         if <-closed {             return         }     } } func main() {     /**     建立监听链接     */     ln, err := net.Listen("tcp", "127.0.0.1:6010")     if err != nil {         panic(err)     }     //创建一个管道     //talkChan := map[f]     talkChan := make(map[int]chan string)     fmt.Printf("%p\n", talkChan)     /*        监听是否有客户端过来的连接请求     */     for {         fmt.Println("wait connect...")         conn, err := ln.Accept()         if err != nil {             log.Fatal("get client connection error: ", err)         }         go handleConnection(conn, talkChan)     } }

package main import (     "fmt"     "math/rand"     "net" ) func main() {     conn, err := net.Dial("tcp", "127.0.0.1:6010")     if err != nil {         panic(err)     }     fmt.Fprintf(conn, "hello server\n")     defer conn.Close()     go writeFromServer(conn)     for {         var talkContent string         fmt.Scanln(&talkContent)         if len(talkContent) > 0 {             _, err = conn.Write([]byte(talkContent))             if err != nil {                 fmt.Println("write to server error")                 return             }         }     } } func connect() {     conn, err := net.Dial("tcp", "127.0.0.1:6010")     if err != nil {         panic(err)     }     fmt.Fprintf(conn, "hello server\n")     defer conn.Close()     go writeFromServer(conn)     for {         var talkContent string         fmt.Scanln(&talkContent)         if len(talkContent) > 0 {             _, err = conn.Write([]byte(talkContent))             if err != nil {                 fmt.Println("write to server error")                 return             }         }     } } func writeFromServer(conn net.Conn) {     defer conn.Close()     for {         data := make([]byte, 1024)         c, err := conn.Read(data)         if err != nil {             fmt.Println("rand", rand.Intn(10), "have no server write", err)             return         }         fmt.Println(string(data[0:c]) + "\n ")     } }