package cn.hhj.aio;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousChannelGroup;
import java.nio.channels.AsynchronousServerSocketChannel;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * AIO服务端
 */
public class AIOServer {

    private final int port;

    public static void main(String args[]) {
        int port = 8000;
        new AIOServer(port);
    }

    public AIOServer(int port) {
        this.port = port;
        listen();
    }

    private void listen() {
        try {
            ExecutorService executorService = Executors.newCachedThreadPool();
            AsynchronousChannelGroup threadGroup = AsynchronousChannelGroup.withCachedThreadPool(executorService, 1);
            //开门营业
            //工作线程，用来侦听回调的，事件响应的时候需要回调
            final AsynchronousServerSocketChannel server = AsynchronousServerSocketChannel.open(threadGroup);
            server.bind(new InetSocketAddress(port));
            System.out.println("服务已启动，监听端口" + port);

            //准备接受数据
            server.accept(null, new CompletionHandler<AsynchronousSocketChannel, Object>(){
                final ByteBuffer buffer = ByteBuffer.allocateDirect(1024);
                //实现completed方法来回调
                //由操作系统来触发
                //回调有两个状态，成功
                public void completed(AsynchronousSocketChannel result, Object attachment){
                    System.out.println("IO操作成功，开始获取数据");
                    try {
                        buffer.clear();
                        result.read(buffer).get();
                        buffer.flip();
                        result.write(buffer);
                        buffer.flip();
                    } catch (Exception e) {
                        System.out.println(e.toString());
                    } finally {
                        try {
                            result.close();
                            server.accept(null, this);
                        } catch (Exception e) {
                            System.out.println(e.toString());
                        }
                    }

                    System.out.println("操作完成");
                }

                @Override
                //回调有两个状态，失败
                public void failed(Throwable exc, Object attachment) {
                    System.out.println("IO操作是失败: " + exc);
                }
            });

            try {
                Thread.sleep(Integer.MAX_VALUE);
            } catch (InterruptedException ex) {
                System.out.println(ex);
            }
        } catch (IOException e) {
            System.out.println(e);
        }
    }
}