package com.Zhongger;
import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
/**
 * @author zhongmingyi
 * @date 2021/9/15 1:29 下午
 */
public class BIOServer {
    public static void main(String[] args) throws IOException {
        ExecutorService threadPool = Executors.newCachedThreadPool();
        ServerSocket serverSocket = new ServerSocket(8989);
        System.out.println("服務(wù)端已啟動(dòng)");
        while (true) {
            Socket socket = serverSocket.accept();
            threadPool.execute(new Runnable() {
                @Override
                public void run() {
                    handle(socket);
                }
            });
        }
    }
    public static void handle(Socket socket) {
        byte[] bytes = new byte[1024];
        try {
            InputStream inputStream = socket.getInputStream();
            int read = 0;
            while (true) {
                read = inputStream.read(bytes);
                if (read != -1) {
                    System.out.println("客戶端發(fā)送給服務(wù)端的數(shù)據(jù)：" + new String(bytes, 0, read));
                } else {
                    break;
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                socket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

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

		ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
        System.out.println("初始時(shí)-->limit--->" + byteBuffer.limit());
        System.out.println("初始時(shí)-->position--->" + byteBuffer.position());
        System.out.println("初始時(shí)-->capacity--->" + byteBuffer.capacity());
        System.out.println("初始時(shí)-->mark--->" + byteBuffer.mark());
        System.out.println("--------------------------------------");
        // 添加一些數(shù)據(jù)到緩沖區(qū)中
        String s = "后端Dancer";
        byteBuffer.put(s.getBytes());
        // 看一下初始時(shí)4個(gè)核心變量的值
        System.out.println("put完之后-->limit--->" + byteBuffer.limit());
        System.out.println("put完之后-->position--->" + byteBuffer.position());
        System.out.println("put完之后-->capacity--->" + byteBuffer.capacity());
        System.out.println("put完之后-->mark--->" + byteBuffer.mark());
        System.out.println("--------------------------------------");
        byteBuffer.flip();
        System.out.println("flip完之后-->limit--->" + byteBuffer.limit());
        System.out.println("flip完之后-->position--->" + byteBuffer.position());
        System.out.println("flip完之后-->capacity--->" + byteBuffer.capacity());
        System.out.println("flip完之后-->mark--->" + byteBuffer.mark());

	public static void mappedByteBufferTest() throws IOException {
        RandomAccessFile file = new RandomAccessFile("/Users/bytedance/Desktop/file.txt", "rw");
        FileChannel fileChannel = file.getChannel();
        //0～3的位置是直接映射到內(nèi)存中的，可以修改文件中的這部分內(nèi)容
        MappedByteBuffer mappedByteBuffer = fileChannel.map(FileChannel.MapMode.READ_WRITE, 0, 3);
        mappedByteBuffer.put(0, (byte) 'Y');
        mappedByteBuffer.put(2, (byte) 'K');
        file.close();
    }

import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
/**
 * @author zhongmingyi
 * @date 2021/9/16 10:38 下午
 */
public class FileChannelTest {
    public static void main(String[] args) throws IOException {
        String text = "Hello, Zhongger！";
        //創(chuàng)建一個(gè)文件輸出流
        FileOutputStream fileOutputStream = new FileOutputStream("/Users/bytedance/Desktop/file.txt");
        //通過(guò)文件輸出流獲取到FileChannel
        FileChannel fileChannel = fileOutputStream.getChannel();
        //創(chuàng)建一個(gè)ByteBuffer，將數(shù)據(jù)寫入ByteBuffer中
        ByteBuffer buffer = ByteBuffer.allocate(1024);
        buffer.put(text.getBytes());
        //切換成讀模式
        buffer.flip();
        //把ByteBuffer里到數(shù)據(jù)寫入到FileChannel中
        fileChannel.write(buffer);
        //關(guān)閉文件輸出流
        fileOutputStream.close();
    }
}

 	public static void readFromFile() throws IOException {
        //創(chuàng)建一個(gè)文件輸入流
        FileInputStream fileInputStream = new FileInputStream("/Users/bytedance/Desktop/file.txt");
        //通過(guò)文件輸入流獲取到FileChannel
        FileChannel fileChannel = fileInputStream.getChannel();
        //創(chuàng)建一個(gè)ByteBuffer，將Channel的數(shù)據(jù)讀取到ByteBuffer中
        ByteBuffer buffer = ByteBuffer.allocate(1024);
        fileChannel.read(buffer);
        //輸出ByteBuffer中的數(shù)據(jù)
        System.out.println(new String(buffer.array()));
        //關(guān)閉文件輸入流
        fileInputStream.close();
    }

 	public static void readFromOneFileWriteToOtherFile() throws IOException {
        FileInputStream fileInputStream = new FileInputStream("/Users/bytedance/Desktop/file.txt");
        FileOutputStream fileOutputStream = new FileOutputStream("/Users/bytedance/Desktop/file2.txt");
        FileChannel fileInputStreamChannel = fileInputStream.getChannel();
        FileChannel fileOutputStreamChannel = fileOutputStream.getChannel();
        ByteBuffer buffer = ByteBuffer.allocate(1024);
        while (true) {
        	//Buffer復(fù)位，防止越界
            buffer.clear();
            int read = fileInputStreamChannel.read(buffer);
            if (read == -1) {
                break;
            }
            //切讀
            buffer.flip();
            fileOutputStreamChannel.write(buffer);
        }
        fileInputStream.close();
        fileOutputStream.close();
    }

 	public static void transferFrom() throws IOException {
        FileInputStream fileInputStream = new FileInputStream("/Users/bytedance/Desktop/file.txt");
        FileOutputStream fileOutputStream = new FileOutputStream("/Users/bytedance/Desktop/file_copy.txt");
        FileChannel fileInputStreamChannel = fileInputStream.getChannel();
        FileChannel fileOutputStreamChannel = fileOutputStream.getChannel();
        fileOutputStreamChannel.transferFrom(fileInputStreamChannel, 0, fileInputStreamChannel.size());
        fileInputStream.close();
        fileOutputStream.close();
    }

	public static void mappedByteBufferTest() throws IOException {
        RandomAccessFile file = new RandomAccessFile("/Users/bytedance/Desktop/file.txt", "rw");
        FileChannel fileChannel = file.getChannel();
        MappedByteBuffer mappedByteBuffer = fileChannel.map(FileChannel.MapMode.READ_WRITE, 0, 3);
        mappedByteBuffer.put(0, (byte) 'Y');
        mappedByteBuffer.put(2, (byte) 'K');
        file.close();
    }

Selector selector = Selector.open();

channel.configureBlocking(false);
channel.register(selector, SelectionKey.OP_ACCEPT);

abstract SelectableChannel configureBlocking(boolean block)  

SelectionKey.OP_ACCEPT
SelectionKey.OP_WRITE
SelectionKey.OP_READ
SelectionKey.OP_CONNECT

key.attachment(); //返回SelectionKey的attachment，attachment可以在注冊(cè)channel的時(shí)候指定。
key.channel(); // 返回該SelectionKey對(duì)應(yīng)的channel。
key.selector(); // 返回該SelectionKey對(duì)應(yīng)的Selector。
key.interestOps(); //返回代表需要Selector監(jiān)控的IO操作的bit mask
key.readyOps(); // 返回一個(gè)bit mask，代表在相應(yīng)channel上可以進(jìn)行的IO操作。```

		while (true) {
            if (selector.select(1000) == 0) {
                System.out.println("服務(wù)器未連接到客戶端。。。");
                continue;
            }
            Set<SelectionKey> selectionKeys = selector.selectedKeys();
            Iterator<SelectionKey> iterator = selectionKeys.iterator();
            while (iterator.hasNext()) {
                SelectionKey selectionKey = iterator.next();
                if (selectionKey.isAcceptable()) {
                    System.out.println("服務(wù)端接受到了客戶端請(qǐng)求");
                    SocketChannel socketChannel = serverSocketChannel.accept();
                    socketChannel.configureBlocking(false);
                    socketChannel.register(selector, SelectionKey.OP_READ, ByteBuffer.allocate(1024));
                }
                if (selectionKey.isReadable()) {
                    SocketChannel channel = (SocketChannel) selectionKey.channel();
                    ByteBuffer byteBuffer = (ByteBuffer) selectionKey.attachment();
                    channel.read(byteBuffer);
                    System.out.println("from 客戶端 " + new String(byteBuffer.array()));
                }
                iterator.remove();
            }
        }

package com.Zhongger;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.*;
import java.util.Iterator;
import java.util.Set;
/**
 * @author zhongmingyi
 * @date 2021/9/15 3:00 下午
 */
public class NIOServer {
    public static void main(String[] args) throws IOException {
        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
        serverSocketChannel.bind(new InetSocketAddress(8886));
        serverSocketChannel.configureBlocking(false);
        Selector selector = Selector.open();
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
        while (true) {
            if (selector.select(1000) == 0) {
                System.out.println("服務(wù)器未連接到客戶端。。。");
                continue;
            }
            Set<SelectionKey> selectionKeys = selector.selectedKeys();
            Iterator<SelectionKey> iterator = selectionKeys.iterator();
            while (iterator.hasNext()) {
                SelectionKey selectionKey = iterator.next();
                if (selectionKey.isAcceptable()) {
                    System.out.println("服務(wù)端接受到了客戶端請(qǐng)求");
                    SocketChannel socketChannel = serverSocketChannel.accept();
                    socketChannel.configureBlocking(false);
                    socketChannel.register(selector, SelectionKey.OP_READ, ByteBuffer.allocate(1024));
                }
                if (selectionKey.isReadable()) {
                    SocketChannel channel = (SocketChannel) selectionKey.channel();
                    ByteBuffer byteBuffer = (ByteBuffer) selectionKey.attachment();
                    channel.read(byteBuffer);
                    System.out.println("from 客戶端 " + new String(byteBuffer.array()));
                }
                iterator.remove();
            }
        }
    }
}

package com.Zhongger;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;
/**
 * @author zhongmingyi
 * @date 2021/9/24 1:27 下午
 */
public class NIOClient {
    public static void main(String[] args) throws IOException {
        SocketChannel socketChannel = SocketChannel.open();
        socketChannel.configureBlocking(false);
        InetSocketAddress inetSocketAddress = new InetSocketAddress("127.0.0.1", 8886);
        //連接服務(wù)器
        if (!socketChannel.connect(inetSocketAddress)) {
            while (!socketChannel.finishConnect()) {
                System.out.println("連接需要時(shí)間，客戶端不會(huì)阻塞，可以做其他工作");
            }
        }
        //連接成功，發(fā)送數(shù)據(jù)
        String str = "Hello,Zhongger!";
        ByteBuffer byteBuffer = ByteBuffer.wrap(str.getBytes());
        socketChannel.write(byteBuffer);
        System.in.read();
    }
}