NIO學習筆記（4）-- 【練習】NIO聊天工具

通過NIO的學習，自己簡單寫了一個，C/S架構的聊天工具。

Server端：

    1.接受客戶端Channel。

    2.記錄客戶端集合clients。利用channel進行區分客戶端，後續可以添加一個ID。

    3.客戶端通過遍歷clients，對除發送者以外的所有客戶端通訊。

Client端：

    1.發送請求。

    2.接收內容

    3.獲取控制檯內容，併發送

待解決問題：

       由於獲取控制檯數據的流，System.in是阻塞的IO：

     

ReadableByteChannel in=Channels.newChannel(System.in);
ByteBuffer buffer = ByteBuffer.allocate(1024);
in.read(buffer);//這裏會阻塞

所以每次接收消息的話，並需控制檯觸發一下，不知道有沒有好的方法，還請知道的大牛指導下，謝謝

以下是代碼：

public class NioServer {
	private static Set<SocketChannel> clients=new HashSet<SocketChannel>();
	
	public static void main(String[] args) {
		ServerSocketChannel serverChannel;
		Selector selector;
		
		try{
			//服務端的準備
			serverChannel= ServerSocketChannel.open();
			ServerSocket serverSocket=serverChannel.socket();
			serverSocket.bind(new InetSocketAddress(12345));
			serverChannel.configureBlocking(false);
			selector=Selector.open();
			serverChannel.register(selector, SelectionKey.OP_ACCEPT);
		} catch (IOException e){
			e.printStackTrace();
			return;
		}
		
		while(true){
			try {
				selector.select();
				System.out.println("======select========");
			} catch (IOException e) {
				e.printStackTrace();
				break;
			}
			Iterator<SelectionKey> iterator = selector.selectedKeys().iterator();
			
			while(iterator.hasNext()){
				SelectionKey key=iterator.next();
				iterator.remove();
				
				try {
					if(key.isAcceptable()){
						System.out.println("=============accept============");
						ServerSocketChannel server = (ServerSocketChannel) key.channel();
						SocketChannel client=server.accept();//接受客戶端的請求
						client.configureBlocking(false);//客戶端 服務端 全都設置爲 非阻塞
						
						clients.add(client);
						client.register(key.selector(), SelectionKey.OP_READ);
					}
					if(key.isReadable()){
						System.out.println("=============read==============="+clients);
						SocketChannel client=(SocketChannel) key.channel();
						ByteBuffer buffer=ByteBuffer.allocate(1024);
						if(client.read(buffer)>0){
							Iterator<SocketChannel> it=clients.iterator();
							while(it.hasNext()){
								SocketChannel other=it.next();
								if(other != client){
									buffer.flip();
									other.write(buffer);
								}
							}
						}
						
						key.interestOps(SelectionKey.OP_READ);
					}
				} catch (IOException e) {
					e.printStackTrace();
					
				}
			}
		}
	}
}

private String name="A";
	
	public void execute(){
		try {
			SocketChannel client = SocketChannel.open();
			Selector selector = Selector.open();
			
			client.configureBlocking(false);
			client.connect(new InetSocketAddress("127.0.0.1", 12345));
			//註冊監聽Connect
			client.register(selector, SelectionKey.OP_CONNECT,name);
			while(true){
				int n = selector.select();
				if(n==0){
					continue;
				}
				Iterator<SelectionKey> iterator=selector.selectedKeys().iterator();
				while(iterator.hasNext()){
					SelectionKey key=iterator.next();
					iterator.remove();
					
					if(key.isConnectable() && client.finishConnect()){
						System.out.println("[client]:連接成功");
						ByteBuffer buffer = ByteBuffer.allocate(1024);
						buffer.put(name.getBytes());
						buffer.flip();
						client.write(buffer);
						
						key.interestOps(SelectionKey.OP_READ | SelectionKey.OP_WRITE);
					}
					if(key.isReadable()){
						System.out.println("[client]:開始接受");
						ByteBuffer buffer = ByteBuffer.allocate(1024);
						WritableByteChannel out = Channels.newChannel(System.out);
						while(client.read(buffer)>0){
							System.out.println("==============");
							buffer.flip();
							out.write(buffer);
						}
						key.interestOps(SelectionKey.OP_READ | SelectionKey.OP_WRITE);
					}
					if(key.isWritable()){
						ReadableByteChannel in=Channels.newChannel(System.in);
						ByteBuffer buffer = ByteBuffer.allocate(1024);
						
						if(in.read(buffer)>0){
							buffer.flip();
							SocketChannel channel = (SocketChannel) key.channel();
							channel.write(buffer);
							buffer.clear();
						}
						key.interestOps(SelectionKey.OP_READ);
					}
				}
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
		
	}