2

由于某种原因，我的 erlang 服务器在每次请求后都会生成一个 case_clause 错误。这是我的代码：
keychain_no_auth_handler.erl

-module(keychain_no_auth_handler).
-export(
  [ init/3, 
    content_types_accepted/2,
    terminate/3,
    allowed_methods/2,
    handle_request/2
  ]).

-export([is_registered/1]).

init(_Transport, _Req, []) -> {upgrade, protocol, cowboy_rest}.

terminate(_Reason, _Req, _State) -> ok.

allowed_methods(Req, State) -> {[<<"POST">>], Req, State}.

content_types_accepted(Req, State) -> {[{<<"application/json">>, handle_request}], Req, State}.

handle_request(Req, State) ->
    {Action, Req2} = cowboy_req:binding(action, Req),

    {Reply, Req3} = case Action of
        <<"registered">> -> is_registered(Req2)
    end,

    {ok, Req4} = cowboy_req:reply(200, [{<<"content-type">>, <<"application/json">>}], Reply, Req3),
   {ok, Req4, State}
.

is_registered(Req) ->
    {Number, Req2} = cowboy_req:qs_val(<<"number">>, Req),
    Reply = backend:is_registered(Number),
    {Reply, Req2}
.

is_registered [函数]

is_registered(Number) ->
    emysql:prepare(is_registered, <<"SELECT `device`.`id` FROM `device` WHERE `device`.`number`= ?">>),
    ResultPacket = emysql:execute(auth_pool, is_registered, [Number]),
    ResultType = is_record(ResultPacket, result_packet),

    case ResultType of
        true -> 
            Field = emysql_util:as_proplist(ResultPacket),
            Id = proplists:get_value(<<"device.id">>, Field),
            Registered = Id >= 0,

            case Registered of
                true -> 
                    Reply = {[{response, registered}]},
                    jiffy:encode(Reply)
                ;
                false -> 
                    Reply = {[{response, available}]},
                    jiffy:encode(Reply)
            end;
        false -> 
            Reply = {[{response, error}]},
            jiffy:encode(Reply)
    end
.

服务器回复适当的响应，然后在每次请求后生成 case_clause 错误：

=错误报告==== 5-Feb-2014::10:32:39 === 节点“keychain@dnldd”上的进程 <0.182.0> 出错，退出值：{{case_clause,{ok,{http_req ,#Port<0.2286>,ranch_tcp,keepalive,<0.182.0>,<<4 bytes>>,'HTTP/1.1',{{127,0,0,1},49720},<<9 bytes>> ,undefined,4004,<<11 bytes>>,undefined,<<0 bytes>>,[],[{action,<<10 bytes>>}],[{<<4 bytes>>,<<14 bytes >>},{<<10 字节>>,<<10 字节>>},{<<14 字节>>,<<1 字节>>},{<<13 字节>>,<<8 字节>> },{<<6 字节>>,<<51 字节>>},{<<6 字节>>,<<12 字节>>},{<<12 字节>>,<<16 字节>>}, {<<10 字节>>,<<120 字节>>},{<<13 字节>>,<<36 字节>>},{<<6 字节>>,<<3 字节>>},{<<3 字节>>,<<1 字节>>},{<<15 字节>>, <<17 字节>>},{<<15 字节>>,<<14 字节>>}],[{<<12 字节>>,{<<11 字节>>,<<4 字节>>,[ ]}},{<<17 bytes>>,undefined},{<<13 bytes>>,undefined},{<<19 bytes>>,undefined},{<<8 bytes>>,undefined},{< <6 字节>>,[...{<<13 字节>>,未定义},{<<19 字节>>,未定义},{<<8 字节>>,未定义},{<<6 字节>>,[...{<<13 字节>>,未定义},{<<19 字节>>,未定义},{<<8 字节>>,未定义},{<<6 字节>>,[...

=错误报告==== 2014 年 2 月 5 日::10:32:39 === 牧场侦听器 keychain_http 在 <0.182.0> 退出时使用 cowboy_protocol:start_link/4 启动了连接过程，原因是：{{case_clause,{好的,{http_req,#Port<0.2286>,ranch_tcp,keepalive,<0.182.0>,<<"POST">>,'HTTP/1.1',{{127,0,0,1},49720},< <"127.0.0.1">>,undefined,4004,<<"/registered">>,undefined,<<>>,[],[{action,<<"registered">>}],[{<< "host">>,<<"127.0.0.1:4004">>},{<<"connection">>,<<"keep-alive">>},{<<"content-length">>, <<"0">>},{<<"缓存控制">>,<<"无缓存">>},{<<"origin">>,<<"chrome-extension://fhbjgbiflinjbdggehcddcbncdddomop">>},{<<"number">>,<<"233265256262">>},{<<"content-type">>,<<"application/json ">>},{<<"user-agent">>,<<"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/32.0.1700.107 Safari/537.36"> >},{<<"邮递员令牌">>,<<"61b7c8f0-b4f8-3bde-8b99-67c141242e5a">>},{<<"接受">>,<<""user-agent">>,<<"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/32.0.1700.107 Safari/537.36">>},{<<"postman -token">>,<<"61b7c8f0-b4f8-3bde-8b99-67c141242e5a">>},{<<"接受">>,<<""user-agent">>,<<"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/32.0.1700.107 Safari/537.36">>},{<<"postman -token">>,<<"61b7c8f0-b4f8-3bde-8b99-67c141242e5a">>},{<<"接受">>,<<"/ ">>},{<<"dnt">>,<<"1">>},{<<"accept-encoding">>,<<"gzip,deflate,sdch">>},{< <"accept-language">>,<<"en-US,en;q=0.8">>}],[{<<"content-type">>,{<<"application">>,<< "json">>,[]}},{<<"if-modified-since">>,undefined},{<<"if-none-match">>,undefined},{<<"if-unmodified -since">>,undefined},{<<"if-match">>,undefined},{<<"accept">>,[{{<<" ">>,<<" ">>,[ ]},1000,[]}]},{<<"connection">>,[<<"keep-alive">>]}],undefined,[{charset,undefined},{media_type,{<<"text">>,<<"html">>,[]}}],等待,未定义,<<>>,true,done,[],< <>>,undefined},undefined}},[{cowboy_rest,process_content_type,3,[{file,"src/cowboy_rest.erl"},{line,780}]},{cowboy_protocol,execute,4,[{file ,"src/cowboy_protocol.erl"},{line,529}]}]}

我在这里做错了什么？谢谢。

4

2 回答 2

3

我想通了，需要为请求设置响应并返回它。cowboy_rest 自动处理实际的回复。

handle_request(Req, State) ->
    {Action, Req2} = cowboy_req:binding(action, Req),

    {Reply, Req3} = case Action of
        <<"registered">> -> is_registered(Req2)
    end,

    Req3 = cowboy_req:set_resp_body(Reply, Req3),
    {true, Req2, State}
.
于 2014-02-06T11:17:33.083 回答
0

尝试将您的 handle_request 中的返回元组更改为：

{好的，请求，状态}

至：

{真，请求，状态}

于 2014-02-05T13:26:44.767 回答