NioServer

package linag.test.dubbo.core.netty;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.util.Iterator;
import java.util.Set;


public class NioServer {
    public static void main(String[] args) throws IOException {
        Selector selector = Selector.open();
        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
        serverSocketChannel.configureBlocking(false);
        serverSocketChannel.socket().bind(new InetSocketAddress(11000));
        //注册一个ServerSocketChannel并监听accept事件
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT );

        serverSocketChannel = ServerSocketChannel.open();
        serverSocketChannel.configureBlocking(false);
        serverSocketChannel.socket().bind(new InetSocketAddress(11001));
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT  );

        for(;;) {
            // 当注册事件到达时，方法返回，否则该方法会一直阻塞
            int nReadyChannels = selector.select();
            System.out.println("nReadyChannels:" + nReadyChannels);
            if(nReadyChannels == 0 ) {
                continue;
            }
            // 获得selector中选中的相的迭代器，选中的相为注册的事件
            Set<SelectionKey> selectionKeys = selector.selectedKeys();
            Iterator<SelectionKey> iterator = selectionKeys.iterator();
            while (iterator.hasNext()) {
                SelectionKey selectionKey = iterator.next();
                //如果有客户端连接进来
                if(selectionKey.isAcceptable()) {
                    ServerSocketChannel selectedServerSocketChannel = (ServerSocketChannel)selectionKey.channel();
                    SocketChannel channel = selectedServerSocketChannel.accept();
                    channel.configureBlocking(false);
                    channel.register(selector, SelectionKey.OP_READ);
                }else if(selectionKey.isReadable()) {
                    ByteBuffer buffer = ByteBuffer.allocate(100);
                    SocketChannel socketChannel = (SocketChannel)selectionKey.channel();
                    while (socketChannel.read(buffer) > 0) {
                        buffer.flip();
                        while (buffer.hasRemaining()) {
                            System.out.println((char)buffer.get());
                        }
                        buffer.clear();
                    }
                }
            }
            iterator.remove();
        }


    }
}