Go Language Practice _ implement one (client) to one (server-side) Chat room

First, the purpose

Use the go language to implement a server-side chat room with the client.

Software: goland,go1.9

Code Warehouse Address

Second, the idea

1, first start the server side, using the Listen_socket function to listen to the IP address of the client connection;

2, start the client, and send data to the server side, send the end of the port block, waiting for server-side messages;

3, the server receives the message sent by the client;

4, the server sends the data to the client, after the sending is finished;

5, the client receives a message sent by the server side, the port is blocked after the send end, waiting for the client's message;

6, repeat step 2-5;

7, if the server side receives the "close" message sent by the client, the server side closes the connection with the client, and continues to wait for the next client connection;

8, the client closes, the chat ends.

Third, Go Code implementation

Sever End

//One-to-one chatroom SeverPackage Mainimport ("FMT"    "Net")//var connmap map[string]*net. TcpconnFunc Main () {listen_socket, err:= Net. Listen ("TCP","127.0.0.1:8000")//turn on the listener interface    ifErr! = Nil {//If there is an errorFmt. Println ("Sever Error")} defer listen_socket. Close ()//Delay server-side shutdownFmt. Println ("Sever is wating ....")     for{conn, err:= Listen_socket. Accept ()//listening to the port of the client        ifErr! =Nil {fmt. Println ("Conn fail ...")} FMT. Println ("Connect client successed")//Show server-side connectivity Success        varMsgstring  //declaring msg as a string variable         for {            //start receiving messages sent by clientsmsg =""  //string msg is initially emptyData: = Make ([]byte,255)//Create and declare a data variable, 255-bitMsg_read, ERR: = conn. Read (data)//receive messages sent by the client, bytes assigned to Msg_read,err as error            ifMsg_read = =0|| Err! = Nil {//If the message read is 0 bytes or there is an errorFmt. Println ("Err")} MSG_READ_STR:=string(data[0: Msg_read])//Converts a msg_read_str byte format into a string form            ifMsg_read_str = ="Close"{//if the received client message is closeConn. Write ([]byte("Close"))                 Break            }            //FMT. Println (String (Data[0:msg_read]))Fmt. Println ("client say:", MSG_READ_STR)//receiving information from the clientFMT. Printf ("say to client:")//prompt to the client to say the wordsFmt. Scan (&MSG)//Enter the server side to say to the client//Conn. Write ([]byte ("Hello client\n"))//msg_write: = []byte (msg)Conn. Write ([]byte(msg))//Send the message to the client//server-side port congestion is caused here} fmt. Println ("Client close\n") Conn. Close ()//Close Connection    }}

Client Side

//One-to-one chatroom ClientPackage Mainimport ("FMT"    "Net") Func Main () {conn, err:= Net. Dial ("TCP","127.0.0.1:8000")    ifErr! =Nil {fmt. Println ("Conn fail ...")} Defer conn. Close () fmt. Println ("Connect Sever successed")    varMsgstring  //declaring msg as a string variable     for{msg=""  //initialize MSG as null valueFmt. Printf ("say to sever:") fmt. Scan (&MSG)//Enter the message that the client will send to the server side//FMT. PRINTLN (msg)//msg_write: = []byte (msg)//Conn. Write (Msg_write)Conn. Write ([]byte(msg))//information into byte stream form and send to server side//This causes the client program port to clog//FMT. Println ([]byte (msg))//wait for the server to send information backData: = Make ([]byte,255) Msg_read, err:=Conn. Read (data)ifMsg_read = =0|| Err! =Nil {fmt. Println ("Err")} MSG_READ_STR:=string(data[0: Msg_read]) ifMsg_read_str = ="Close"{Conn. Write ([]byte("Close"))             Break} fmt. Println ("Sever say:", Msg_read_str)} Conn. Close ()}

Iv. Summary

• Write, Read, conn, scan function can cause the program to jam;
• In the network, the data is usually transmitted in bytes, so the format conversion is required: The byte is sent by the string, and when it is received, the byte is converted to a string.