public class BIOserver {
    public static void main(String[] args) throws IOException {
        // 為了方便直接用了Executors創(chuàng)建線程池
        ExecutorService service = Executors.newCachedThreadPool();
        //指定服務(wù)端端口
        ServerSocket serverSocket = new ServerSocket(6666);
        System.out.println("服務(wù)器啟動");
        while(true){
            //阻塞等待連接
            Socket socket = serverSocket.accept();
            System.out.println("連接到一個客戶端");
            //每個連接對應(yīng)一個線程
            service.execute(new Runnable() {
                @Override
                public void run() {
                    try {
                        handler(socket);
                    }catch (Exception e){
                        e.printStackTrace();
                    }
                }
            });
        }
    }
    public static void handler(Socket socket) throws IOException {
        System.out.println("Thread:"+Thread.currentThread().getId());
        byte[] bytes = new byte[1024];
        InputStream inputStream = socket.getInputStream();
        while (true){
            //阻塞等待讀取
            int n = inputStream.read(bytes);
            if(n!=-1){
                System.out.println(new String(bytes,0,n));
            }else {
                break;
            }
        }
        socket.close();
    }
}

public class BufferNio {
    public static void main(String[] args) {
        //創(chuàng)建buffer容量為5個int
        IntBuffer buffer = IntBuffer.allocate(5);
        //放數(shù)據(jù)
        buffer.put(1);
        buffer.put(2);
        buffer.put(3);
        buffer.put(4);
        buffer.put(5);
        //讀寫切換
        buffer.flip();
        //取數(shù)據(jù)
        //內(nèi)部維護一個索引，每次get索引都會往后邊移動
        while(buffer.hasRemaining()){
            System.out.println(buffer.get());
        }
    }
}

    // Invariants: mark <= position <= limit <= capacity
    private int mark = -1;
    private int position = 0;
    private int limit;
    private int capacity;

    public final Buffer flip() {
        limit = position;
        position = 0;
        mark = -1;
        return this;
    }

        buffer.limit(2);
        buffer.position(1);

public class ChannelNio {
    public static void main(String[] args) throws IOException {
        String str = "少壯不努力，老大徒傷悲";
        //創(chuàng)建輸出流
        FileOutputStream os = new FileOutputStream("D:\\xxxxxxxxxxxxxxxxxxx\\a.txt");
        //獲取FileChannel
        FileChannel channel = os.getChannel();
        //創(chuàng)建緩沖
        ByteBuffer buffer = ByteBuffer.allocate(1024);
        //把字符串放入緩沖區(qū)
        buffer.put(str.getBytes());
        //反轉(zhuǎn)ByteBuffer
        buffer.flip();
        //將ByteBuffer寫入到FileChannel
        channel.write(buffer);
        //關(guān)閉流
        os.close();
    }
}

public class ChannelNio {
    public static void main(String[] args) throws IOException {
        FileInputStream is = new FileInputStream("D:\\xxxxxxxxxxxxxxxxxxx\\a.txt");
        FileChannel channel = is.getChannel();
        ByteBuffer buffer = ByteBuffer.allocate(1024);
        channel.read(buffer);
        System.out.println(new String(buffer.array()));
        is.close();
    }
}

public class ChannelNio {
    public static void main(String[] args) throws IOException {
        FileInputStream is = new FileInputStream("D:\\xxxxxxxxxxxxxxxxxxx\\a.txt");
        FileChannel channel = is.getChannel();
        ByteBuffer buffer = ByteBuffer.allocate(1024);
        FileOutputStream os = new FileOutputStream("D:\\xxxxxxxxxxxxxxxxxxx\\b.txt");
        FileChannel osChannel = os.getChannel();
        while (true){
            buffer.clear();
            int i = channel.read(buffer);
            if(i==-1){
                break;
            }
            buffer.flip();
            osChannel.write(buffer);
        }
        is.close();
        os.close();
    }
}

public class ChannelNio {
    public static void main(String[] args) throws IOException {
        FileInputStream is = new FileInputStream("D:\\xxxxxxxxxxxxxxxxxxx\\HELP.md");
        FileChannel channel = is.getChannel();
        FileOutputStream os = new FileOutputStream("D:\\xxxxxxxxxxxxxxxxxxx\\HELP222.md");
        FileChannel osChannel = os.getChannel();
        osChannel.transferFrom(channel,0,channel.size());
        is.close();
        os.close();
    }
}