转载：第一个Erlang 小程序

学了Erlang三个礼拜，做了这个程序，费了4天时间，这四天查阅了wxwidgts，wxErlang，等界面设计的资料，英文还是不行 呀！今天被老大说我的程序使用的协议不规范。我想这算个RC版吧，哈哈。本程序使用Erlang + wxErlang + mysql。Erlang这东西不火，也是个麻烦，Web上Erlang的资料可怜地少，先贴个效果图吧。

这个程序：不小心搞了个变量去匹配消息，然后变量不变这个害我好惨。记住：Erlang变量特性，变量不变

程序很拙劣，但我还是想贴出来，以示我Erlang入门了，哈哈。

客户端：client.erl 服务端：server.erl

程序：在线多人聊天系统

服务器端代码：

-module(server).

-export([start/0]).

 

% 启动一个服务器

start() ->

case gen_tcp:listen(1110,[binary,{packet,0},{reuseaddr,true},{active,true}]) of

{ok,Listen} ->

spawn(fun() -> par_connect(Listen) end);

{error,Why} ->

io:format(“server start error,the reason maybe ~p~n

now is going restart~n“,[Why]),

end.

% 建立链接

start()

par_connect(Listen) ->

case gen_tcp:accept(Listen) of

{ok,Socket} ->

spawn(fun() -> par_connect(Listen) end),

loop(Socket);

{error,Why} ->

io:format(“create internet connect failed,the reasom maybe ~p~n

now is going reconnect~n“,[Why]),

par_connect(Listen)

end.

% 监听消息

loop(Socket) ->

receive

{tcp,Socket,Bin} ->

case binary_to_term(Bin) of

{login,Username,Password} -> % 请求登入聊天系统

handleLoginRequest(Username,Password,Socket),

loop(Socket);

{socket,ChatRoom} -> % 用户选择了聊天房间

handleChoseRoom(ChatRoom,Socket),

loop(Socket);

{msg,ChatRoom,Username,Msg} -> % 用户发送聊天信息

handleChatMsg(ChatRoom,Username,Msg),

loop(Socket);

{totalusers,ChatRoom} -> % 用户请求在线总人数

handleTotalUsersRequest(ChatRoom,Socket),

loop(Socket);

{logintimes,Username} -> % 用户请求登入系统次数

handleLoginTimesRequest(Username,Socket),

loop(Socket);

{chattimes,Username} -> % 用户请求聊天次数

handleChatTimesRequest(Username,Socket),

loop(Socket);

{lastlogin,Username} -> % 用户请求最近一次登陆系统时间

handleLastLoginRequest(Username,Socket),

loop(Socket)

end;

{tcp_closed,Socket} -> % 用户登出聊天系统

handleTcpClosed(Socket),

loop(Socket)

end.

% 请求登入聊天系统

handleLoginRequest(Username,Password,Socket) ->

mysql:start_link(chat,“localhost”,“root”,“weihua0620″,“test”), % 链接数据库

case checkAccount(Username,Password) of % 检测用户名，密码是否合法

ok -> RoomList = getChatRoomList(); % 合法，获取聊天房间

nok -> RoomList = []    % 不合法，返回空聊天房间

end,

% 向客户端发送聊天房间列表

gen_tcp:send(Socket,term_to_binary({roomlist,RoomList})),

% 登入成功 更新登入次数 和 最后一次登陆时间

case RoomList of

[] -> loginfailed;

_ ->

Sql1 = lists:concat(["select login_times from account

where username = '",Username,"'"]),

case mysql:fetch(chat,Sql1) of % 提取登入次数

{data,Result} ->

[[Logintimes]] = mysql:get_result_rows(Result),

Sql2 = lists:concat(["update account set login_times = ",

Logintimes+1," where username = '",Username,"'"]), mysql:fetch(chat,Sql2); % 更新登入次数

{error,_Result} -> no

end,

Sql3 = lists:concat(["update account set last_login = now()

where username = '",Username,"'"]), mysql:fetch(chat,Sql3) % 更新最近一次登入时间

end.

 

% 检查用户名，密码是否正确

checkAccount(Username,Password) ->

Sql = lists:concat(["select * from account where username = '",

Username,"'and    password = '",Password,"'"]),

case mysql:fetch(chat,Sql) of

{data,Result} ->

case mysql:get_result_rows(Result) of

[] -> nok; % 用户名，密码有误

_ -> ok    % 用户名，密码有效

end;

{error,_Result} ->

checkAccount(Username,Password)

end.

 

% 获取聊天房间列表

getChatRoomList() ->

Sql = “select roomname from chatroom” ,

case mysql:fetch(chat,Sql) of

{data,Result} ->

case mysql:get_result_rows(Result) of

[] -> [];

RoomList -> binaryToList(RoomList) % 处理提取出来的二进制数据

end;

{error,_Result} ->

getChatRoomList()

end.

binaryToList([]) -> [];

binaryToList([[H]|T]) ->

[binary_to_list(H)|binaryToList(T)].

% 用户选择了聊天房间,保存当前 Socket handleChoseRoom(ChatRoom,Socket) ->

Soc = binary_to_list(base64:encode(term_to_binary(Socket))),

Sql = lists:concat(["insert into roomsocket values('",ChatRoom,"','",Soc,"')"]),

mysql:fetch(chat,Sql).

 

% 用户发送聊天信息

handleChatMsg(ChatRoom,Username,Msg) ->

% 更新用户聊天次数，每发一条聊天 msg ，聊天次数 +1

Sql = lists:concat(

["select chat_times from account where username = '",Username,"'"] ),

case mysql:fetch(chat,Sql) of

{data,Result} ->

[[Chattimes]] = mysql:get_result_rows(Result),

Sql2 = lists:concat(["update account set chat_times = ",Chattimes+1,

" where username = '",Username,"'"]),

mysql:fetch(chat,Sql2);

{error,_Result} -> no

end,

% 在聊天房间广播用户Username 的 Msg

sendRoomMsg(ChatRoom,Username,Msg).

 

% 向聊天房间广播用户 Username 的消息 Msg sendRoomMsg(ChatRoom,Username,Msg) ->

Sql = lists:concat(

["select socket from roomsocket where roomname = '",ChatRoom,"'"] ),

case mysql:fetch(chat,Sql) of

{data,Result} ->

case mysql:get_result_rows(Result) of

[] -> nosocket;

SocketList ->

Sockets = binaryToList(SocketList), % 处理提取出来的二进制数据

sendMessage(Username,Sockets,Msg)

end;

{error,_Result} ->

sendRoomMsg(ChatRoom,Username,Msg)

end.

 

% 向房间内的所有用户（socket识别）广播消息 sendMessage(_Username,[],_Msg) ->[]; sendMessage(Username,Sockets,Msg) ->

[H|T] = Sockets,

Socket = binary_to_term(base64:decode(H)),

gen_tcp:send(Socket,term_to_binary({msg,Username,Msg})),

sendMessage(Username,T,Msg).

 

% 用户请求在线总人数

handleTotalUsersRequest(ChatRoom,Socket) ->

Sql = lists:concat(

["select count(socket) from roomsocket where roomname = '",ChatRoom,"'"]),

case mysql:fetch(chat,Sql) of

{data,Result} ->

[[Num]] = mysql:get_result_rows(Result),

gen_tcp:send(Socket,term_to_binary({totalusers,Num}));

{error,_Result} -> no

end.

 

% 用户请求登入系统次数

handleLoginTimesRequest(Username,Socket) ->

Sql = lists:concat(

["select login_times from account where username = '",Username,"'"]),

case mysql:fetch(chat,Sql) of

{data,Result} ->

[[LoginTimes]] = mysql:get_result_rows(Result),

gen_tcp:send(Socket,term_to_binary({logintimes,LoginTimes}));

{error,_Result} -> no

end.

% 用户请求聊天次数

handleChatTimesRequest(Username,Socket) ->

Sql = lists:concat(

["select chat_times from account where username = '",Username,"'"]),

case mysql:fetch(chat,Sql) of

{data,Result} ->

[[ChatTimes]] = mysql:get_result_rows(Result),

gen_tcp:send(Socket,term_to_binary({chattimes,ChatTimes}));

{error,_Result} ->no

end.

 

% 用户请求最近一次登陆系统时间

handleLastLoginRequest(Username,Socket) ->

Sql = lists:concat(

["select last_login from account where username = '",Username,"'"]),

case mysql:fetch(chat,Sql) of

{data,Result} ->

[[{ datetime,

{{Year,Month,Day},

{Hour,Minute,Second}} }]] =mysql:get_result_rows(Result), LastLoginTime = lists:concat(

[Year,":",Month,":",Day," ",Hour,":",Minute,":",Second] ), gen_tcp:send(Socket,term_to_binary({lastlogin,LastLoginTime}));

{error,_Result} ->no

end.

 

% 用户退出了聊天系统，删除用户的在数据库中的 socket记录

handleTcpClosed(Socket) ->

Soc = binary_to_list(base64:encode(term_to_binary(Socket))),

Sql = lists:concat(["delete from roomsocket where socket = '",Soc,"'"]),

mysql:fetch(chat,Sql).

 

客户端代码：

-module(client).

-include_lib(“wx/include/wx.hrl”).

start() ->

Username = checkLoginInputInfo(usernameDialog()), % 获取登入用户名

Password = checkLoginInputInfo(passwordDialog()), % 获取用户密码

Socket = connect(), % 建立Tcp链接，获取Socket

ChatRoomList = loginServer(Username,Password,Socket), % 登入服务器，获取聊天房间列表

ChatRoom = checkLoginInputInfo(choseChatRoom(ChatRoomList)), % 获取用户选择的聊天房间

loginChatRoom(Username,ChatRoom,Socket).    % 登入聊天房间

% 获取登入用户名

usernameDialog() ->

Prompt = “Please entry your username!”,

CaptionInfo = “Login chat system”,

wx:new(),

Dialog = wxTextEntryDialog:new(wx:null(),Prompt,[{caption,CaptionInfo}]),

case wxTextEntryDialog:showModal(Dialog) of

?wxID_OK ->

Str = wxTextEntryDialog:getValue(Dialog);

?wxID_CANCEL ->

Str = null

end, wxTextEntryDialog:destroy(Dialog), Str.

% 获取用户密码

passwordDialog() ->

Prompt = “Please entry the password”,

CaptionInfo = “Login chat system”,

wx:new(),

Dialog = wxPasswordEntryDialog:new(wx:null(),Prompt,[{caption,CaptionInfo}]),

case wxPasswordEntryDialog:showModal(Dialog) of

?wxID_OK ->

Str = wxPasswordEntryDialog:getValue(Dialog);

?wxID_CANCEL ->

Str = null

end, wxPasswordEntryDialog:destroy(Dialog), Str.

% 消息对话框，给 消息事件 调用

messageDialog(Prompt,CaptionInfo) ->

wx:new(),

Dialog = wxMessageDialog:new(wx:null(),Prompt,[{caption,CaptionInfo},{style,?wxO

K bor ?wxICON_INFORMATION}]),

wxMessageDialog:showModal(Dialog),

wxMessageDialog:destroy(Dialog).

% 检测 Str 是否为空 ，即：用户名，用户密码，所选聊天房间

checkLoginInputInfo(Str) ->

case Str of

null ->

wx:new(),

Prompt = “Thank you for use!”,

CaptionInfo = “Logout chat system”,

messageDialog(Prompt,CaptionInfo),

exit(self()); % 如果用户在某次选择了cancel，表明用户向退出聊天系统，即退出

_ -> Str

end.

% 与服务器建立链接，返回 Socket

connect() ->

case gen_tcp:connect(“localhost”,1110,[binary,{packet,0}]) of

{ok,Socket} ->

wx:new(),

Prompt = “Connect to the server success!”,

CaptionInfo = “Connect to the server …”,

messageDialog(Prompt,CaptionInfo),

Socket;

{error,Why} ->

CaptionInfo = “Connect to the server failed,is reconnecting”,

messageDialog(Why,CaptionInfo),

connect()

end.

% 登入服务器，登入成功获取聊天房间列表

loginServer(Username,Password,Socket) ->

gen_tcp:send(Socket,term_to_binary({login,Username,Password})),

receive

{tcp,Socket,Bin} ->

ChatRoomList = binary_to_term(Bin)

end,

case ChatRoomList of

{roomlist,[]} -> % 服务器返回聊天房间为空，表明 用户名/密码 有误

Prompt = “username or password error! please try again!”,

CaptionInfo = “Login chat system failed”,

messageDialog(Prompt,CaptionInfo),

start();

{roomlist,RoomList} -> RoomList

end.

% 选择聊天房间

choseChatRoom(ChatRoomList) ->

Prompt = “Please select the chat room!”,

CaptionInfo = “Chat room list”,

wx:new(),

Dialog = wxSingleChoiceDialog:new(wx:null(),Prompt,CaptionInfo,ChatRoomList),

case wxSingleChoiceDialog:showModal(Dialog) of

?wxID_OK ->

ChatRoom = wxSingleChoiceDialog:getStringSelection(Dialog);

?wxID_CANCEL ->

ChatRoom = null

end,

wxSingleChoiceDialog:destroy(Dialog),

ChatRoom.

% 登入聊天房间

loginChatRoom(Username,ChatRoom,Socket) ->

% 向服务器发送登入的聊天房间，服务收到该信息后，保存对该用户的链接的socket

gen_tcp:send(Socket,term_to_binary({socket,ChatRoom})),

CaptionInfo = “Online chat system — “++ChatRoom ++ ” — ” ++Username,

wx:new(),

% 聊天主框架

Frame = wxFrame:new(wx:null(),?wxID_ANY, CaptionInfo,[{pos,{300,300}},{size,{400,300}},

{style,?wxDEFAULT_FRAME_STYLE band (bnot(?wxRESIZE_BORDER bor ?wxMAXIMIZE BOX))}]),

% 聊天信息显示窗口

TextDisplay = wxTextCtrl:new(Frame,?wxID_ANY,

[{pos,{0,0}}, {size,{393,150}},{style,?wxTE_MULTILINE}]),

% 聊天信息输入窗口

TextInput = wxTextCtrl:new(Frame,?wxID_ANY,

[{pos,{0,150}}, {size,{393,80}},{style,?wxTE_MULTILINE}]),

setup(Frame,TextDisplay,TextInput),

wxFrame:show(Frame), loop(Frame,TextDisplay,TextInput,ChatRoom,Username,Socket),

wx:destory().

% 绘制聊天窗口

setup(Frame,TextDisplay,TextInput) ->

MenuBar = wxMenuBar:new(),

Account = wxMenu:new(),

Statistics = wxMenu:new(),

Help = wxMenu:new(),

SendMessage = wxMenu:new(),

wxMenu:append(Help,?ABOUT,“About chat system”), wxMenu:append(Statistics,?ONLINEUSERNUM,“online users”), wxMenu:append(Account,?LOGINTIMES,“login times”), wxMenu:append(Account,?CHATTIMES,“chat times”), wxMenu:append(Account,?MYACCOUNT,“my account”), wxMenu:append(Account,?EXIT,“QUIT”), wxMenu:append(SendMessage,?SENDMSG,“Send Message”),

wxMenuBar:append(MenuBar,Account,“&Account”), wxMenuBar:append(MenuBar,Statistics,“&Statistics”), wxMenuBar:append(MenuBar,Help,“&Help”), wxMenuBar:append(MenuBar,SendMessage,“&SendMessage”),

wxFrame:setMenuBar(Frame,MenuBar),

wxTextCtrl:setEditable(TextDisplay,false),% 显示窗口不允许用户输入信息

wxTextCtrl:setEditable(TextInput,true),

wxFrame:createStatusBar(Frame), wxFrame:setStatusText(Frame,“Welcome to chat system!”),

wxFrame:connect(Frame,command_menu_selected), wxFrame:connect(Frame,close_window).

% 消息控制,监听窗口消息以及服务器发送过来的消息

loop(Frame,TextDisplay,TextInput,ChatRoom,Username,Socket) ->

receive

% 退出聊天系统

#wx{id = ?EXIT, event = #wxCommand{type=command_menu_selected}} ->

wxWindow:close(Frame,[]);

% 查看帮助信息

#wx{id = ?ABOUT,event = #wxCommand{type=command_menu_selected}} ->

wx:new(),

Prompt = “Chat online system”,

CaptionInfo = “About”,

messageDialog(Prompt,CaptionInfo),

loop(Frame,TextDisplay,TextInput,ChatRoom,Username,Socket);

% 查看在线用户数量

#wx{id = ?ONLINEUSERNUM,event = #wxCommand{type = command_menu_selected}} ->

gen_tcp:send(Socket,term_to_binary({totalusers,ChatRoom})),

loop(Frame,TextDisplay,TextInput,ChatRoom,Username,Socket);

% 查看登陆次数

#wx{id = ?LOGINTIMES,event = #wxCommand{type = command_menu_selected}} ->

gen_tcp:send(Socket,term_to_binary({logintimes,Username})),

loop(Frame,TextDisplay,TextInput,ChatRoom,Username,Socket);

% 查看聊天次数

#wx{id = ?CHATTIMES,event = #wxCommand{type = command_menu_selected}} ->

gen_tcp:send(Socket,term_to_binary({chattimes,Username})),

loop(Frame,TextDisplay,TextInput,ChatRoom,Username,Socket);

% 查看我上一次登陆时间

#wx{id = ?MYACCOUNT,event = #wxCommand{type = command_menu_selected}} ->

gen_tcp:send(Socket,term_to_binary({lastlogin,Username})), loop(Frame,TextDisplay,TextInput,ChatRoom,Username,Socket);

% 发送聊天消息

#wx{id = ?SENDMSG,event = #wxCommand{type = command_menu_selected}} ->

Msg = wxTextCtrl:getValue(TextInput), % 获取输入消息

gen_tcp:send(Socket,term_to_binary({msg,ChatRoom,Username,Msg})),

wxTextCtrl:clear(TextInput), % 清空输入框

loop(Frame,TextDisplay,TextInput,ChatRoom,Username,Socket);

% 收取来自服务器的消息

{tcp,Socket,Bin} ->

case binary_to_term(Bin) of

% 聊天消息

{msg,User_name,Msg} ->

wxTextCtrl:writeText(TextDisplay,User_name++” >> “++Msg++“r“);

% 登陆次数

{logintimes,LoginTimes} ->

wx:new(),

Prompt = lists:concat(["Your total login times is ",LoginTimes]),

CaptionInfo = “Login Times”, messageDialog(Prompt,CaptionInfo);

% 聊天次数

{chattimes,ChatTimes} ->

wx:new(),

Prompt = lists:concat(["Your total chat times is ",ChatTimes]),

CaptionInfo = “Chat Times”, messageDialog(Prompt,CaptionInfo);

% 最近一次登陆时间

{lastlogin,LastTime} ->

wx:new(),

Prompt = io_lib:format(“Your last login times is ~p“,[LastTime]),

CaptionInfo = “Last login Time”, messageDialog(Prompt,CaptionInfo);

% 在线用户数目

{totalusers,TotalUserNum} ->

wx:new(),

Prompt = lists:concat(["Current online user number is",TotalUserNum]),

CaptionInfo = “Online user num”,

messageDialog(Prompt,CaptionInfo)

end,

loop(Frame,TextDisplay,TextInput,ChatRoom,Username,Socket)

end.

程序运行：

输入用户名

输入密码

聊天展示

请求在线人数

目前聊天室Education在线人数 3人

请求 登入次数

用户 hua 登入过 4次

请求 聊天次数

用户 hua 的聊天次数共 6次

请求 最近一次登入系统的时间

用户 hua 最近一次登入系统时间 2011:7:13 14:49:28

用户 退出聊天室

数据库设计，共三个表

表：account

表 chatroom

表 roomsocket