Eshell V5.10.4 (abort with ^G)
1> bank_server3:create_account(name1, 1000).
true
2> name1 ! check.
Current money is: 1000
check
3> erlang:send(name1, check).
Current money is: 1000
check
4> erlang:send(name1, abcd).
handle_info: abcd
abcd
Yearly Payment: 940 -> 880
5> gen_server:cast(name1, msg1).
handle_cast: msg1
ok
6> gen_server:cast(name123, msg1).
ok
7> name123 ! check.
** exception error: bad argument
in operator !/2
called as name123 ! check
Yearly Payment: 880 -> 820
8> gen_server:call(name1, msg1).
handle_call: msg1
ok
9> erlang:send(name1, stop1).
Receive STOP1
terminate: "Force STOP"
stop1
10>
=ERROR REPORT==== 15-Jan-2015::09:02:35 ===
** Generic server <0.34.0> terminating
** Last message in was stop1
** When Server state == 820
** Reason for termination ==
** "Force STOP"
Eshell V5.10.4 (abort with ^G)
1> bank_server3:create_account(name2, 1000).
true
2> name2 ! stop2.
Receive STOP2
terminate: normal
stop2
-module(bank_server3).
-behaviour(gen_server).
-export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
-export([create_account/2]).
-define(I(F), io:format(F++"~n", [])).
-define(I(F, A), io:format(F++"~n", A)).
% --------------------------------------------------------------------
% API
% --------------------------------------------------------------------
%%'银行开户，并存入初始金额
-spec create_account(Name, Money) -> any() when
Name :: atom(),
Money :: integer().
create_account(Name, Money)->
%% gen_server:start(Mod, Args, Options)
{ok, Pid} = gen_server:start(?MODULE, [Money], []),
%% 假设年费为10
Pid ! {yearly, 60},
erlang:register(Name, Pid).
% --------------------------------------------------------------------
% Callback
% --------------------------------------------------------------------
init([Money]) ->
{ok, Money}.
handle_call(check, _From, Money) ->
{reply, Money, Money};
handle_call(Request, _From, State) ->
?I("handle_call: ~p", [Request]),
Reply = ok,
{reply, Reply, State}.
handle_cast(Msg, State) ->
?I("handle_cast: ~p", [Msg]),
{noreply, State}.
%%'存钱
handle_info({deposit, AddMoney}, Money) ->
NewMoney = Money + AddMoney,
?I("deposit money: ~w -> ~w", [Money, NewMoney]),
{noreply, NewMoney};
%%.
%%'取钱(可透支)
handle_info({cash1, SubMoney}, Money) ->
NewMoney = Money - SubMoney,
?I("deposit money: ~w -> ~w", [Money, NewMoney]),
{noreply, NewMoney};
%%.
%%'取钱(不可透支)
handle_info({cash2, SubMoney}, Money) ->
NewMoney = Money - SubMoney,
case NewMoney > 0 of
true ->
%% 支取成功
?I("deposit money: ~w -> ~w", [Money, NewMoney]),
{noreply, NewMoney};
false ->
%% 支取失败 提示余额不足
?I("Insufficient balance, current money is ~w", [Money]),
{noreply, Money}
end;
%%.
%%'扣年费（这里假设10秒为一年）
handle_info({yearly, Payment}, Money) ->
Year = case get(year) of
undefined ->
put(year, 0),
0;
Y ->
YY = Y + 1,
put(year, YY),
YY
end,
erlang:send_after(60 * 1000, self(), {yearly, Payment}),
Reply = if
Money =< 0 ->
%% 没有钱可以扣
Money;
Year =:= 0 ->
%% 还不到一年，不用扣
Money;
true ->
NewMoney = Money - Payment,
case NewMoney > 0 of
true ->
%% 扣费成功
?I("Yearly Payment: ~w -> ~w", [Money, NewMoney]),
NewMoney;
false ->
%% 余额不足以扣年费，则扣到0为止
?I("Yearly Payment: ~w -> ~w", [Money, 0]),
0
end
end,
{noreply, Reply};
%%.
%%'查询
handle_info(check, Money) ->
?I("Current money is: ~w", [Money]),
{noreply, Money};
handle_info({From, check}, Money) ->
%% ?I("Send result to: ~w", [From]),
From ! {self(), Money},
{noreply, Money};
%%.
handle_info(stop1, Money) ->
?I("Receive STOP1"),
Reason = "Force STOP",
{stop, Reason, Money};
handle_info(stop2, Money) ->
?I("Receive STOP2"),
Reason = normal,
{stop, Reason, Money};
handle_info(Info, State) ->
?I("handle_info: ~p", [Info]),
{noreply, State}.
terminate(Reason, _State) ->
?I("terminate: ~p", [Reason]),
ok.
code_change(_OldVsn, State, _Extra) ->
{ok, State}.