客户端和服务端Socket流

客户端代码：

public class NIOClient {
    public static void main(String[] args) throws IOException {
            try {
                SocketChannel socketChannel=SocketChannel.open();
                socketChannel.configureBlocking(false);
                Selector selector=Selector.open();
                //监听客户端是否发起连接
                socketChannel.register(selector, SelectionKey.OP_CONNECT);
                socketChannel.connect(new InetSocketAddress("127.0.0.1",8899));

                while (true){
                    selector.select();
                    Set<SelectionKey> selectionKeys=selector.selectedKeys();

                    for (SelectionKey  selectionKey:selectionKeys){
                        if (selectionKey.isConnectable()){
                            SocketChannel client= (SocketChannel) selectionKey.channel();

                            if (client.isConnectionPending()){
                                client.finishConnect();
                                ByteBuffer writeBuffer=ByteBuffer.allocate(1024);

                                writeBuffer.put((LocalDateTime.now()+"连接成功").getBytes());
                                writeBuffer.flip();
                                client.write(writeBuffer);

                                ExecutorService executorService= Executors.newSingleThreadExecutor(Executors.defaultThreadFactory());
                                executorService.submit(()->{
                                   while(true){
                                        try{
                                            writeBuffer.clear();
                                            InputStreamReader input=new InputStreamReader(System.in);
                                            BufferedReader bufferedReader=new BufferedReader(input);
                                            String message=bufferedReader.readLine();

                                            writeBuffer.put(message.getBytes());
                                            writeBuffer.flip();
                                            client.write(writeBuffer);
                                        }
                                        catch (Exception e){
                                            e.printStackTrace();
                                        }
                                   }
                                });
                            }
                            client.register(selector,SelectionKey.OP_READ);
                        }else if (selectionKey.isReadable()){
                            SocketChannel client= (SocketChannel) selectionKey.channel();

                            ByteBuffer readBuffer=ByteBuffer.allocate(1024);
                            int count=client.read(readBuffer);

                            if (count>0){
                                String receiveMessage=new String(readBuffer.array(),0,count);
                                System.out.println(receiveMessage);
                            }
                        }

                    }
                    selectionKeys.clear();
                }

            }
            catch (Exception e){
                e.printStackTrace();
            }
    }
}

服务端代码：

public class NIOServer {
    private  static Map<String, SocketChannel>  clientMap=new HashMap<>();
    public static void main(String[] args) throws IOException {
        ServerSocketChannel serverSocketChannel=ServerSocketChannel.open();
        serverSocketChannel.configureBlocking(false);
        serverSocketChannel.socket().bind(new InetSocketAddress(8899));

        Selector selector=Selector.open();
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);

        while (true){
            try {
                selector.select();

                Set<SelectionKey> selectionKeys=selector.selectedKeys();

                selectionKeys.forEach(selectionKey -> {
                    final  SocketChannel client;
                        try {
                            if (selectionKey.isAcceptable()){
                                ServerSocketChannel serverSocketChannel1= (ServerSocketChannel) selectionKey.channel();
                                client=serverSocketChannel1.accept();
                                client.configureBlocking(false);
                                client.register(selector,SelectionKey.OP_READ);

                                String key="["+ UUID.randomUUID().toString()+"]";
                                clientMap.put(key,client);

                            }
                            else if(selectionKey.isReadable()){
                                    client= (SocketChannel) selectionKey.channel();
                                    ByteBuffer readBuffer=ByteBuffer.allocate(1024);

                                    int count=client.read(readBuffer);

                                    if (count>0){
                                        readBuffer.flip();
                                        Charset charset=Charset.forName("utf-8");
                                        String reciveString=String.valueOf(charset.decode(readBuffer).array());
                                        System.out.println(client+":"+reciveString);

                                        String senderKey=null;
                                        for (Map.Entry<String,SocketChannel> entry : clientMap.entrySet()){
                                            if (client == entry.getValue()){
                                                senderKey=entry.getKey();
                                                break;
                                            }
                                        }
                                        for (Map.Entry<String,SocketChannel> entry : clientMap.entrySet()){
                                            SocketChannel socketChannel=entry.getValue();
                                            ByteBuffer writeBuffer=ByteBuffer.allocate(1024);
                                            writeBuffer.put((senderKey+":"+reciveString).getBytes());

                                            writeBuffer.flip();
                                            socketChannel.write(writeBuffer);
                                        }
                                    }
                            }


                        } catch (IOException e) {
                            e.printStackTrace();
                        }

                });
                //将key清空，相当于Itetor一次性remove
                selectionKeys.clear();

            }
            catch (Exception e){
                e.printStackTrace();
            }

        }
    }
}