cowboy的get和post的例子

官方get和post的代码是有问题的，1.1下运行crash，这里修改了下，贴代码

创建工程

rebar-creator create-app testCowboy

testCowboy_app.erl

-module(testCowboy_app).

-behaviour(application).

-export([start/2, stop/1]).

-define(C_ACCEPTORS,  100).

start(_StartType, _StartArgs) ->
    application:start(crypto),
    application:start(cowlib),
    application:start(ranch),
    application:start(cowboy),

    Routes    = route_helper:get_routes(),
    Dispatch  = cowboy_router:compile(Routes),
    Port      = 8080,
    TransOpts = [{port, Port}],
    ProtoOpts = [{env, [{dispatch, Dispatch}]}],
    cowboy:start_http(http, ?C_ACCEPTORS, TransOpts, ProtoOpts).

stop(_State) ->
    ok.

route_helper.erl

-module(route_helper).

-export([get_routes/0]).

get_routes() ->
    [
        {'_', [
            {"/get",  get_handler, []},
            {"/post", post_handler, []}
        ]}
    ].

get_handler.erl

-module(get_handler).

-export([init/3]).
-export([handle/2]).
-export([terminate/3]).

init(_Transport, Req, []) ->
    {ok, Req, undefined}.

handle(Req, State) ->
    {Method,_} = cowboy_req:method(Req),
    {Val,_} = cowboy_req:qs_val(<<"test_get">>,Req),
    {ok, Req2} = handle_params(Method, Val, Req),
    {ok, Req2, State}.

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

%% private
handle_params(<<"GET">>, undefined, Req) ->
    cowboy_req:reply(400, [], <<"Missing echo parameter.">>, Req);
handle_params(<<"GET">>, Val, Req) ->
    cowboy_req:reply(200, [
        {<<"content-type">>, <<"text/plain; charset=utf-8">>}
    ], Val, Req);
handle_params(_, _, Req) ->
    %% Method not allowed.
    cowboy_req:reply(405, Req).

post_handler.erl

-module(post_handler).

-export([init/3]).
-export([handle/2]).
-export([terminate/3]).

init(_Transport, Req, []) ->
    {ok, Req, undefined}.

handle(Req, State) ->
    {Method,_} = cowboy_req:method(Req),
    HasBody = cowboy_req:has_body(Req),
    {ok, Req2} = handle_params(Method, HasBody, Req),
    {ok, Req2, State}.

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

%% private
handle_params(<<"POST">>, true, Req) ->
    {ok, PostVals, Req2} = cowboy_req:body_qs(Req),
    Echo = proplists:get_value(<<"echo">>, PostVals),
    echo(Echo, Req2);
handle_params(<<"POST">>, false, Req) ->
    cowboy_req:reply(400, [], <<"Missing body.">>, Req);
handle_params(_, _, Req) ->
    %% Method not allowed.
    cowboy_req:reply(405, Req).

echo(undefined, Req) ->
    cowboy_req:reply(400, [], <<"Missing echo parameter.">>, Req);
echo(Echo, Req) ->
    cowboy_req:reply(200, [
        {<<"content-type">>, <<"text/plain; charset=utf-8">>}
    ], Echo, Req).

get的测试url

http://127.0.0.1:8080/get?test_get=b

post的测试

http://127.0.0.1:8080/post
字段echo，value随便