10、NIO--DategramChannel

DatagramChannel

 Java NIO中的DatagramChannel是一个能收发
　　UDP包的通道。
 操作步骤：
　　打开 DatagramChannel
　　接收/发送数据

服务端

    @Test
    public void receive() throws IOException{
        DatagramChannel dc = DatagramChannel.open();
        
        dc.configureBlocking(false);
        
        dc.bind(new InetSocketAddress(8082));
        
        //选择器
        Selector selector = Selector.open();
        
        dc.register(selector, SelectionKey.OP_READ);
        
        while(selector.select() > 0){
            Iterator<SelectionKey> it =  selector.selectedKeys().iterator();
            
            while(it.hasNext()){
                SelectionKey sk = it.next();
                
                if(sk.isReadable()){
                    ByteBuffer buf = ByteBuffer.allocate(1024);
                    
                    //接收数据
                    dc.receive(buf);
                    buf.flip();
                    System.out.println(new String(buf.array(),0,buf.limit()));
                    
                }
            }
            it.remove();
        }
    }

客户端：

    @Test
    public void send() throws IOException{
        
        DatagramChannel dc = DatagramChannel.open();
        
        dc.configureBlocking(false);
        
        ByteBuffer buf = ByteBuffer.allocate(1024);
        
        buf.put("MeChengs".getBytes());
        buf.flip();
        dc.send(buf, new InetSocketAddress("127.0.0.1", 8082));
        
        dc.close();
    }