package com.njq.study.socket.aio;

public class AsyncTimeServer {
 
    public static void main(String[] args) {
        AsyncTimeServerHandler timeServer = new AsyncTimeServerHandler(9999);
        new Thread(timeServer, "AIO-AsyncTimeServerHandler-001").start();
    }
 
}

package com.njq.study.socket.aio;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.channels.AsynchronousServerSocketChannel;
import java.util.concurrent.CountDownLatch;

/**
 * @author: nijiaqi
 * @date: 2019/12/18
 */
public class AsyncTimeServerHandler implements Runnable {
    private int port;
    CountDownLatch latch;
    AsynchronousServerSocketChannel asynchronousServerSocketChannel;

    public AsyncTimeServerHandler(int port) {
        this.port = port;
        try {
            asynchronousServerSocketChannel = AsynchronousServerSocketChannel.open();
            asynchronousServerSocketChannel.bind(new InetSocketAddress(port));
            System.out.println("The time server is start in port:" + port);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        latch = new CountDownLatch(1);
        doAccept();
        try {
            latch.await();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public void doAccept() {
        asynchronousServerSocketChannel.accept(this, new AcceptCompletionHandler());
    }
}

package com.njq.study.socket.aio;

import com.njq.study.socket.aio.AsyncTimeServerHandler;
import com.njq.study.socket.aio.ReadCompletionHandler;

import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;

/**
 * @author: nijiaqi
 * @date: 2019/12/18
 */
public class AcceptCompletionHandler implements CompletionHandler<AsynchronousSocketChannel,AsyncTimeServerHandler> {

    @Override
    public void completed(AsynchronousSocketChannel result, AsyncTimeServerHandler attachment) {
        attachment.asynchronousServerSocketChannel.accept(attachment, this);
        ByteBuffer buffer = ByteBuffer.allocate(1024);
        result.read(buffer, buffer, new ReadCompletionHandler(result));
    }

    @Override
    public void failed(Throwable exc, AsyncTimeServerHandler attachment) {
        exc.printStackTrace();
        attachment.latch.countDown();
    }
}

package com.njq.study.socket.aio;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;

class ReadCompletionHandler implements CompletionHandler<Integer, ByteBuffer> {
    
    private AsynchronousSocketChannel channel;
    
    public ReadCompletionHandler(AsynchronousSocketChannel channel) {
        if (this.channel == null) {
            this.channel = channel;
        }
    }
 
    /**
     * 成功状态回调
     * @param result
     * @param attachment 
     */
    @Override
    public void completed(Integer result, ByteBuffer attachment) {
        attachment.flip();
        byte[] body = new byte[attachment.remaining()];
        attachment.get(body);
        try {
            String req = new String(body);
            System.out.println("The time server receive order : " + req);
            String currentTime = "QUERY TIME ORDER".equalsIgnoreCase(req) 
                    ? new java.util.Date(System.currentTimeMillis()).toString() : "BAD ORDER";
            doWrite(currentTime);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    /**
     * 分离出写模块
     * @param response 
     */
    private void doWrite(String response) {
        if (response != null && response.trim().length() > 0) {
            byte[] bytes = response.getBytes();
            ByteBuffer writeBuffer = ByteBuffer.allocate(bytes.length);
            writeBuffer.put(bytes);
            writeBuffer.flip();
            channel.write(writeBuffer, writeBuffer,
                new CompletionHandler<Integer, ByteBuffer>() {
                    
                    /**
                     * 成功状态回调
                     * @param result
                     * @param buffer 
                     */
                    @Override
                    public void completed(Integer result, ByteBuffer buffer) {
                        // 有可能写半包，若真如此则继续写
                        if (buffer.hasRemaining()) {
                            channel.write(buffer, buffer, this);
                        }
                    }
 
                    /**
                     * 失败状态回调
                     * @param exc
                     * @param attachment 
                     */
                    @Override
                    public void failed(Throwable exc, ByteBuffer attachment) {
                        try {
                            channel.close();
                        } catch(IOException e) {
                            e.printStackTrace();
                        }
                    }
                }
            );
        }
    }
 
    /**
     * 失败状态回调
     * @param exc
     * @param attachment 
     */
    @Override
    public void failed(Throwable exc, ByteBuffer attachment) {
        try {
            this.channel.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
}

package com.njq.study.socket.aio;

/**
 * @author: nijiaqi
 * @date: 2019/12/18
 */
public class AsyncTimeClient {
    public static void main(String[] args) {
        int port = 9999;
        new Thread(new AsyncTimeClientHandler("127.0.0.1", port),"asynclient").start();
    }
}

package com.njq.study.socket.aio;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;
import java.util.concurrent.CountDownLatch;

public class AsyncTimeClientHandler implements CompletionHandler<Void, AsyncTimeClientHandler>, Runnable {
    private AsynchronousSocketChannel client;
    private String host;
    private int port;
    private CountDownLatch latch;

    public AsyncTimeClientHandler(String host, int port) {
        this.host = host;
        this.port = port;
        try {
            client = AsynchronousSocketChannel.open();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void run() {
        latch = new CountDownLatch(1);
        client.connect(new InetSocketAddress(host, port), this, this);
        try {
            latch.await();
        } catch (InterruptedException e1) {
            e1.printStackTrace();
        }
        try {
            client.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void completed(Void result, AsyncTimeClientHandler attachment) {
        byte[] req = "QUERY TIME ORDER".getBytes();
        ByteBuffer writeBuffer = ByteBuffer.allocate(req.length);
        writeBuffer.put(req);
        writeBuffer.flip();
        client.write(writeBuffer, writeBuffer,
                new CompletionHandler<Integer, ByteBuffer>() {
                    @Override
                    public void completed(Integer result, ByteBuffer buffer) {
                        if (buffer.hasRemaining()) {
                            client.write(buffer, buffer, this);
                        } else {
                            ByteBuffer readBuffer = ByteBuffer.allocate(1024);
                            client.read(
                                    readBuffer,
                                    readBuffer,
                                    new CompletionHandler<Integer, ByteBuffer>() {
                                        @Override
                                        public void completed(Integer result,
                                                              ByteBuffer buffer) {
                                            buffer.flip();
                                            byte[] bytes = new byte[buffer
                                                    .remaining()];
                                            buffer.get(bytes);
                                            String body;
                                            try {
                                                body = new String(bytes,
                                                        "UTF-8");
                                                System.out.println("Now is : "
                                                        + body);
                                                latch.countDown();
                                            } catch (UnsupportedEncodingException e) {
                                                e.printStackTrace();
                                            }
                                        }

                                        @Override
                                        public void failed(Throwable exc,
                                                           ByteBuffer attachment) {
                                            try {
                                                client.close();
                                                latch.countDown();
                                            } catch (IOException e) {
                                                // ingnore on close
                                            }
                                        }
                                    });
                        }
                    }

                    @Override
                    public void failed(Throwable exc, ByteBuffer attachment) {
                        try {
                            client.close();
                            latch.countDown();
                        } catch (IOException e) {
                            // ingnore on close
                        }
                    }
                });
    }

    @Override
    public void failed(Throwable exc, AsyncTimeClientHandler attachment) {
        exc.printStackTrace();
        try {
            client.close();
            latch.countDown();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}