push研究——Apache Mina探索初步

        虽然google为Android开发者提供了GCM实现push，但是因为需要系统安装了google play、google帐号、系统>2.2、google push服务器在国外等多种原因，在中国，Android上想实现push还需要自己努力。

        当前最火的开源push是基于xmpp协议的androidpn。androidpn是基于Mina框架的，所以这里从Mina框架开始入手。看mina官网的说明：

  

Server

下面通过简单的例子来学习mina的使用。首先创建服务端，工程正使用了3个jar包

                       

看代码：

public class HelloMina {
	private static final int PORT = 9125;
	  /**
	   * @param args
	   * @throws IOException 
	   */
	  public static void main(String[] args) throws IOException {
		  //创建一个非阻塞的server端Socket ，用NIO
		  IoAcceptor acceptor = new  NioSocketAcceptor();  
	      acceptor.getFilterChain().addLast( "logger", new LoggingFilter() );
	      acceptor.getFilterChain().addLast( "codec", new ProtocolCodecFilter( new TextLineCodecFactory( Charset.forName( "UTF-8" ))));
	      // 设定服务器端的消息处理器
	      acceptor.setHandler(  new MinaServerHandler() );	    
	      acceptor.getSessionConfig().setReadBufferSize( 2048 );
	      acceptor.getSessionConfig().setIdleTime( IdleStatus.BOTH_IDLE, 10 );
	      // 服务器端绑定的端口  启动服务
	      acceptor.bind( new InetSocketAddress(PORT) );
	          
	  	}
}

HelloMina的处理器：

/**
 * HelloMina的处理逻辑
 * @author zhangxy
 */
class MinaServerHandler extends IoHandlerAdapter {
	 @Override
	    public void exceptionCaught( IoSession session, Throwable cause ) throws Exception{
	        cause.printStackTrace();
	        session.close();
	    }

	    @Override
	    public void messageReceived( IoSession session, Object message ) throws Exception
	    {
	        String str = message.toString();
	        if( str.trim().equalsIgnoreCase("quit") ) {
	            session.close();
	            return;
	        }
	        System.err.println("收到客户端发来的消息：："+str);  
	        StringBuilder buf = new StringBuilder(str.length());  
	        for (int i = str.length() - 1; i >= 0; i--) {  
	            buf.append(str.charAt(i));  
	        }  
	  
	        // and write it back.  
	        session.write(buf.toString()); 
	    }

	    @Override
	    public void sessionIdle( IoSession session, IdleStatus status ) throws Exception{
	        System.out.println( "IDLE " + session.getIdleCount( status ));
	    }

		@Override
		public void messageSent(IoSession session, Object message)
				throws Exception {
			// TODO Auto-generated method stub
			super.messageSent(session, message);
			
		}

		@Override
		public void sessionClosed(IoSession session) throws Exception {
			// TODO Auto-generated method stub
			super.sessionClosed(session);
			 System.out.println( "session closed");
		}

		@Override
		public void sessionCreated(IoSession session) throws Exception {
			// TODO Auto-generated method stub
			super.sessionCreated(session);
			 System.out.println( "session create");
		}

		@Override
		public void sessionOpened(IoSession session) throws Exception {
			// TODO Auto-generated method stub
			super.sessionOpened(session);
			 System.out.println( "session opened");
		}
	    
}

client

下面是Client代码，Client没有使用NIO，使用的普通socket实现：

public class HelloMinaClient {
    private Socket socket;  
    private DataOutputStream out;  
    private DataInputStream in;  
    public HelloMinaClient() throws IOException {  
    }  
  
    /** 
     * @param args 
     */  
    public static void main(String[] args) throws Exception {  
        // TODO Auto-generated method stub  
    	HelloMinaClient minaClient = new HelloMinaClient();  
    	minaClient.minaClient();  
    }  
  
    /** 
     *   发送消息 
     * @param out 
     */  
    public void sendMessage(Socket s) {  
        try {  
             out = new DataOutputStream(s.getOutputStream());   
            out.writeBytes("mina\n");  
        } catch (IOException e) {  
            // TODO Auto-generated catch block  
            e.printStackTrace();  
        }  
  
    }  
      
    public void receiveMessage(Socket s) {  
        try {  
             in = new DataInputStream(s.getInputStream());  
             System.err.println("收到服务端发来的消息：："+in.readLine());  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
    }  
  
    public void minaClient() throws Exception {  
        while (true) {  
            try {  
            	socket = new Socket("192.168.21.121", 9124);  
                sendMessage(socket);  
                receiveMessage(socket);  
                out.close();  
                in.close();  
                Thread.sleep(5000);  
            } catch (InterruptedException e) {  
                // TODO Auto-generated catch block  
                e.printStackTrace();  
            } catch(Exception e){  
                e.printStackTrace();  
            }finally {  
                 try{  
                   if(socket!=null)socket.close();  //断开连接  
                 }catch (IOException e) {e.printStackTrace();}  
              }  
        }  
    }  

}

SOCKET作为短连接，即收发消息后SOCKET断开一次，线程过5秒又建立连接收发消息。

/**
* @author 张兴业
* 邮箱：xy-zhang#163.com
* android开发进阶群：278401545
* http://blog.csdn.net/xyz_lmn
*/