这是在Web上实现UDP/TCP API的草案，沿未形成标准。该标准的一大亮点就是使用内置Promise设计模式，替代了传统JavaScript中的事件触发回调。不过各大浏览器厂商会不会这样实现还要打一个问号，毕竟编写标准的学院派和实现标准的行业派很难达到完全统一。

       接口标准提供对原始UDP套接字(Socket)，TCP客户端套接字和TCP服务器套接字API的定义。

简介

       这部分沿未形成规范。您可以使用该API来发送和接收数据，并使用TCP或UDP网络。


使用此API的部分用例：
  • 能够与SMTP, POP3 和 IMAP 服务器进行通信的邮件服务器。
  • 一个能与IRC服务器进行通信的IRC客户端 （注* IRC是一种通过网络的即时聊天方式。其主要用于群组聊天。）
  • 实现一个SSH应用程序
  • 与现有的消费硬件产品进行通信，如互联网电视
  • 游戏服务器
  • 端到端应用程序（注* P2P或对等网络应用）
  • 本地网络多播服务（multicast service）发掘，例如UPnP/ SSDP和mDNS

一个UDP的例子：
  1. // 
  2. // This example shows a simple implementation of UPnP-SSDP M-SEARCH
  3. // discovery using a multicast UDPSocket 
  4. //
  5.       
  6. var address = '239.255.255.250',
  7.     port = '1900',
  8.     serviceType = 'upnp:rootdevice',
  9.     rn = '\r\n',
  10.     search = '';

  12. //  Create a new UDP client socket
  13. var mySocket = new UDPSocket();

  15. // Build an SSDP M-SEARCH multicast message
  16. search += 'M-SEARCH * HTTP/1.1' + rn;
  17. search += 'ST: ' + serviceType + rn;
  18. search += 'MAN: "ssdp:discover"' + rn;
  19. search += 'HOST: ' + address + ':' + port + rn;
  20. search += 'MX: 10';


  23. // Receive and log SSDP M-SEARCH response messages
  24. function receiveMSearchResponses() {         

  26.   // While data in buffer, read and log UDP message
  27.   while (mySocket.readable.state === "readable") {            
  28.     var msg = mySocket.readable.read();
  29.     console.log ('Remote address: ' + msg.remoteAddress + 
  30.                  ' Remote port: ' + msg.remotePort + 
  31.                  'Message: ' + ab2str(msg.data)); 
  32.       // ArrayBuffer to string conversion could also be done by piping 
  33.       // through a transform stream. To be updated when the Streams API
  34.       // specification has been stabilized on this point. 
  35.   }  
  36.       
  37.   // Wait for SSDP M-SEARCH responses to arrive     
  38.   mySocket.readable.wait().then(
  39.     receiveMSearchResponses,          
  40.     e => console.error("Receiving error: ", e);
  41.   );     
  42. }

  44. // Join SSDP multicast group
  45. mySocket.joinMulticast(address);

  47. // Send SSDP M-SEARCH multicast message
  48. mySocket.writeable.write(
  49.   {data : str2ab(search),
  50.    remoteAddress : address,
  51.    remotePort : port
  52.   }).then(
  53.     () => {
  54.       // Data sent sucessfully, wait for response
  55.       console.log('M-SEARCH Sent');
  56.       receiveMSearchResponses();
  57.     },
  58.     e => console.error("Sending error: ", e);
  59. );

  61. // Log result of UDP socket setup. 
  62. mySocket.opened.then(
  63.   () => {
  64.     console.log("UDP socket created sucessfully");
  65.   },
  66.   e =>console.error("UDP socket setup failed due to error: ", e);
  67. );

  69. // Handle UDP socket closed, either as a result of the application 
  70. // calling mySocket.close() or an error causing the socket to be 
  71.    closed.
  72. mySocket.closed.then(
  73.   () => {
  74.      console.log("Socket has been cleanly closed");
  75.   },
  76.   e => console.error("Socket closed due to error: ", e);
  77. );
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相比UDP，TCP的示例代码显得简单一些
  1. // 
  2. // This example shows a simple TCP echo client. 
  3. // The client will send "Hello World" to the server on port **9 and log 
  4. // what has been received from the server.
  5. //   

  7. //  Create a new TCP client socket and connect to remote host     
  8. var mySocket = new TCPSocket("127.0.0.1", **9);

  10. // Send data to server
  11. mySocket.writeable.write("Hello World").then(
  12.     () => {
  13.         
  14.         // Data sent sucessfully, wait for response
  15.         console.log("Data has been sent to server");
  16.         mySocket.readable.wait().then(
  17.             () => {
  18.             
  19.                 // Data in buffer, read it
  20.                 console.log("Data received from server:" + mySocket.readable.read());

  22.                 // Close the TCP connection
  23.                 mySocket.close();
  24.             },
  25.              
  26.             e => console.error("Receiving error: ", e);
  27.         );
  28.     },
  29.     e => console.error("Sending error: ", e);
  30. );

  32. // Signal that we won't be writing any more and can close the write half of the connection.
  33. mySocket.halfClose();

  35. // Log result of TCP connection attempt. 
  36. mySocket.opened.then(
  37.   () => {
  38.     console.log("TCP connection established sucessfully");
  39.   },
  40.   e =>console.error("TCP connection setup failed due to error: ", e);
  41. );

  43. // Handle TCP connection closed, either as a result of the application 
  44. // calling mySocket.close() or the other side closed the TCP  
  45. // connection or an error causing the TCP connection to be closed.
  46. mySocket.closed.then(
  47.   () => {
  48.      console.log("TCP socket has been cleanly closed");
  49.   },
  50.   e => console.error("TCP socket closed due to error: ", e);
  51. );
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       有什么问题可在Github上面给他们开Issues:， 不过关注者廖廖（14个star目前）：https://github.com/sysapps/tcp-udp-sockets/issues