Erlang与ActionScript3采用JSON格式进行Socket通讯

前提：
需要下载来为ActionScript3处理JSON codec

server.erl

-module(server).
-export([start/0,start/1,process/1]).
-define(defPort, 8888).

start() -> start(?defPort).

start(Port) ->
  case gen_tcp:listen(Port, [binary, {packet, 0}, {active, false}]) of
    {ok, LSock} -> server_loop(LSock);
    {error, Reason} -> exit({Port,Reason})
  end.

%% main server loop - wait for next connection, spawn child to process it
server_loop(LSock) ->
  case gen_tcp:accept(LSock) of
    {ok, Sock} ->
      spawn(?MODULE,process,[Sock]),
      server_loop(LSock);
    {error, Reason} ->
      exit({accept,Reason})
  end.

%% process current connection
process(Sock) ->
  Req = do_recv(Sock),
  io:format("~p~n", [Req]),
  {ok, D, []} = rfc4627:decode(Req),
  {obj, [{"name", _Name}, {"age", Age}]} = D,
  Name = binary_to_list(_Name),
  io:format("Name: ~p, Age: ~p~n", [Name, Age]),
  Resp = rfc4627:encode({obj, [{"name", 'Hideto2'}, {"age", 24}]}),
  do_send(Sock,Resp),
  gen_tcp:close(Sock).

%% send a line of text to the socket
do_send(Sock,Msg) ->
  case gen_tcp:send(Sock, Msg) of
    ok -> ok;
    {error, Reason} -> exit(Reason)
  end.

%% receive data from the socket
do_recv(Sock) ->
  case gen_tcp:recv(Sock, 0) of
    {ok, Bin} -> binary_to_list(Bin);
    {error, closed} -> exit(closed);
    {error, Reason} -> exit(Reason)
  end.

Person.as

package
{
    public class Person
    {
        public var name:String;
        public var age:int;
        public function Person()
        {
        }
    }
}

Client.as

package {
    import com.adobe.serialization.json.JSON;

    import flash.display.Sprite;
    import flash.events.*;
    import flash.net.Socket;
    import flash.text.*;

    public class Client extends Sprite
    {
        private var socket:Socket;
        private var myField:TextField;
        private var send_data:Person;
        public function Client()
        {
            socket = new Socket();
            myField = new TextField();
            send_data = new Person();
            send_data.name = "Hideto";
            send_data.age = 23;
            socket.addEventListener(ProgressEvent.SOCKET_DATA, onSocketData);
            socket.connect("localhost", 8888);
            socket.writeUTFBytes(JSON.encode(send_data));
            socket.flush();
            myField.x = 20;
            myField.y = 30;
            myField.text = "test";
            myField.autoSize = TextFieldAutoSize.LEFT;
            addChild(myField);
        }
        private function onSocketData(event:ProgressEvent):void {
            while(socket.bytesAvailable) {
                var recv_data:* = JSON.decode(socket.readUTFBytes(socket.bytesAvailable));
                myField.text = "Name: " + recv_data.name + ", age: " + recv_data.age.toString();
            }
        }
    }
}

运行Erlang服务器端：

Eshell> c(server).
Eshell> server:start().
"{\"name\":\"Hideto\",\"age\":23}"
Name: "Hideto", Age: 23

这里打印出了Erlang Socket Server接收到的AS3 Client发过来的JSON decode过的一个person对象

运行AS3客户端：
client.html上首先显示“test”，然后异步处理完Socket消息发送和接受后，decode Erlang Server端发过来的person对象，将页面上的TextField替换为“Name: Hideto2, age: 24”

原文：http://hideto.iteye.com/blog/235811