关于如何使用CoAP和Java实现基于推送的消息传递系统的任何想法?

时间:2017-05-15 09:49:38

标签: java notifications push coap

我愿意使用CoAP协议来实现基于java推送的消息传递系统。特别是在这样的系统中,客户端仅在与服务器(资源)的连接打开一次,并且服务器以特定速率(例如,每秒10个消息)推送消息(“不可确认”)。但是我没有找到任何现有的解决方案来构建上述系统。

我发现基于拉取的消息传递系统。对于这种情况,客户端打开与服务器的连接,并在一段时间后客户端发送GET请求。然后,服务器处理请求并将单个消息推送(作为响应)到客户端。

因此,对于每个GET,我有一条消息作为响应 - 即双向异步交互。

有没有人知道如何使用CoAP实现基于推送的消息传递系统? CoAP是否支持这样的系统?

基于拉取的消息传递系统实现如下

  1. 服务器部件

        public class CoapServerPartAsync extends CoapServer {
    
                  private static final int COAP_PORT = 8891;
                  private static int incrementor = 1;
                  /*
                  * Application entry point.
                  */
                  public static void main(String[] args) {
    
                     try {
    
                     // create server
                     CoapServerPartAsync server = new CoapServerPartAsync();
    
                     // add endpoints on all IP addresses
    
                     server.addEndpoints();
    
                     server.start();
    
                     } catch (SocketException e) {
    
                          System.err.println("Failed to initialize server: " +   e.getMessage());
                     }
                  }
    
                 /**
                  * Add endpoints listening on default CoAP port on all IP  addresses of all network interfaces.
                  *  
                  * @throws SocketException if network interfaces cannot be determined
                  */
    
                  private void addEndpoints() throws SocketException {
    
    
                      InetSocketAddress bindToAddress = new  InetSocketAddress("127.0.0.1", COAP_PORT);
    
                     addEndpoint(new CoapEndpoint(bindToAddress));
    
                     }
    
                    /*
                     * Constructor for a new Hello-World server. Here, the resources
                     * of the server are initialized.
                     */
                     public CoapServerPartAsync() throws SocketException {
    
                     // provide an instance of a Hello-World resource
                     add(new HelloWorldResource());
                     }
    
                   /*
                    * Definition of the Hello-World Resource
                   */
    
                    class HelloWorldResource extends CoapResource {
    
                          public HelloWorldResource() {
    
                          // set resource identifier
                          super("helloWorld");
    
                         // set display name
                         getAttributes().setTitle("Hello-World Resource");
                     }
    
                     @Override
                     public void handleGET(CoapExchange exchange){
    
                     // respond to the request
                     System.out.println("Push [Hello World!"+(incrementor)+"]");
                      exchange.respond("Hello World!"+(incrementor));
                      incrementor++;
    
                }
           }
     }
    
  2. 客户端部分

          public class CoapClientPartAsync {
    
                        // static boolean getResponse = false;
    
                        public static void main(String args[]) { 
    
                        CoapClient client = new CoapClient("coap://127.0.0.1:8891/helloWorld").useNONs();
    
                       while(true){
                          CoapObserveRelation relation = client.observe( 
             new CoapHandler() {
    
                     @Override public void onLoad(CoapResponse response){
                                String content = response.getResponseText();
                               System.out.println("NOTIFICATION: " + content);
    
                              }
    
                        @Override public void onError() {
                        System.err.println("OBSERVING FAILED (press enter to exit)");
                      }
                   });
                   try {
                         Thread.sleep(1000);
                     }catch (InterruptedException e) {
                          // TODO Auto-generated catch block
                          e.printStackTrace();
                     }       
               }
           }
      }
    

0 个答案:

没有答案