Java NIO——6 基于非阻塞编程UDP NIO的例子

左手的ㄟ右手 2023-06-03 04:58 14阅读 0赞

好吧，承接上篇文章，下面给出一个udp不可靠无连接的例子，他的次传送都是一个udp报文，不向上面文章中tcp是基于流的

代码：

Server:

/**
     * 服务器端
     * 
     * @author Joeson
     * 
     */
    public class UDPServer
    {
    	DatagramChannel channel;
    
    	Selector selector;
    
    	public void work()
    	{
    		try
    		{
    			// 打开一个UDP Channel
    			channel = DatagramChannel.open();
    
    			// 设定为非阻塞通道
    			channel.configureBlocking(false);
    			// 绑定端口
    			channel.socket().bind(new InetSocketAddress(8080));
    
    			// 打开一个选择器
    			selector = Selector.open();
    			channel.register(selector, SelectionKey.OP_READ);
    		} catch (Exception e)
    		{
    			e.printStackTrace();
    		}
    
    		ByteBuffer byteBuffer = ByteBuffer.allocate(65536);
    		while (true)
    		{
    			try
    			{
    				// 进行选择
    				int n = selector.select();
    				if (n > 0)
    				{
    					// 获取以选择的键的集合
    					Iterator iterator = selector.selectedKeys().iterator();
    
    					while (iterator.hasNext())
    					{
    						SelectionKey key = (SelectionKey) iterator.next();
    
    						// 必须手动删除
    						iterator.remove();
    
    						if (key.isReadable())
    						{
    							DatagramChannel datagramChannel = (DatagramChannel) key
    									.channel();
    
    							byteBuffer.clear();
    							// 读取
    							InetSocketAddress address = (InetSocketAddress) datagramChannel
    									.receive(byteBuffer);
    
    							System.out.println(new String(byteBuffer.array()));
    
    							// 删除缓冲区中的数据
    							byteBuffer.clear();
    
    							String message = "data come from server";
    
    							byteBuffer.put(message.getBytes());
    
    							byteBuffer.flip();
    
    							// 发送数据
    							datagramChannel.send(byteBuffer, address);
    						}
    					}
    				}
    			} catch (Exception e)
    			{
    				e.printStackTrace();
    			}
    		}
    
    	}
    
    	public static void main(String[] args)
    	{
    		new UDPServer().work();
    
    	}
    
    }

客户端：

/**
     * 客户端
     * 
     * @author Joeson
     */
    public class UDPClient
    {
    	DatagramChannel channel;
    	Selector selector;
    
    	public void work()
    	{
    
    		try
    		{
    			// 开启一个通道
    			channel = DatagramChannel.open();
    
    			channel.configureBlocking(false);
    
    			SocketAddress sa = new InetSocketAddress("localhost", 8080);
    
    			channel.connect(sa);
    		} catch (Exception e)
    		{
    			e.printStackTrace();
    		}
    
    		try
    		{
    			selector = Selector.open();
    			channel.register(selector, SelectionKey.OP_READ);
    			channel.write(Charset.defaultCharset().encode("data come from client"));
    		} catch (Exception e)
    		{
    			e.printStackTrace();
    		}
    
    		ByteBuffer byteBuffer = ByteBuffer.allocate(100);
    		while (true)
    		{
    			try
    			{
    				int n = selector.select();
    				if (n > 0)
    				{
    
    					Iterator iterator = selector.selectedKeys().iterator();
    
    					while (iterator.hasNext())
    					{
    						SelectionKey key = (SelectionKey) iterator.next();
    						iterator.remove();
    						if (key.isReadable())
    						{
    							channel = (DatagramChannel) key.channel();
    							channel.read(byteBuffer);
    
    							System.out.println(new String(byteBuffer.array()));
    							
    							
    							byteBuffer.clear();
    							
    							channel.write(Charset.defaultCharset().encode(
    									"data come from client"));
    						}
    					}
    				}
    			} catch (Exception e)
    			{
    				e.printStackTrace();
    			}
    		}
    
    	}
    
    	public static void main(String[] args)
    	{
    		new UDPClient().work();
    	}
    }