public void testScannerServer() throws IOException { System.out.println("服务端开启"); ServerSocketChannel serverSocketChannel = ServerSocketChannel.open(); // 非阻塞 serverSocketChannel.configureBlocking(false); serverSocketChannel.bind(new InetSocketAddress(8092)); Selector selector = Selector.open(); serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT); while (selector.select() > 0) { Iterator<SelectionKey> it = selector.selectedKeys().iterator(); while (it.hasNext()) { SelectionKey key = it.next(); // 为何要remove? // https://stackoverflow.com/questions/7132057/why-the-key-should-be-removed-in-selector-selectedkeys-iterator-in-java-ni it.remove(); if (!key.isValid()) { System.out.println("链接不可用"); } else if (key.isAcceptable()) { // 新链接 System.out.println("服务端接受到新链接"); SocketChannel socketChannel = serverSocketChannel.accept(); socketChannel.configureBlocking(false); // 非阻塞 socketChannel.register(selector, SelectionKey.OP_READ); // 注册可读事件 } else if (key.isReadable()) { // 有客户端发送数据 SocketChannel socketChannel = (SocketChannel) key.channel(); // 开始读取数据 System.out.println(new Date().toString()); ByteBuffer byteBuffer = ByteBuffer.allocate(1024); if (socketChannel.read(byteBuffer) == -1) { // -1 说明客户端关闭了写或者直接close System.out.println("客户端关闭链接"); // socketChannel.close(); // 其实不须要调用,由于客户端已经关闭, 为了程序稳健性能够开启 key.cancel(); // 取消注册 } else { byteBuffer.flip(); System.out.println(new String(byteBuffer.array(), 0, byteBuffer.limit())); byteBuffer.clear(); } } } } }