Netty Reactor 模式

单线程 Reactor 模式

示例代码

• EchoServerReactor.java 回显服务器

  package com.netty.im.Reactor.singleThread;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import java.io.IOException;
  import java.net.InetSocketAddress;
  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;
  
  /**
   * Created by andy on 2020/8/21.
   */
  public class EchoServerReactor implements Runnable{
    Selector selector;  // 每个线程配置唯一一个 selector 选择器
    ServerSocketChannel serverSocket; // 服务端监听 channel
    Logger logger = LoggerFactory.getLogger(EchoServerReactor.class);
    
    EchoServerReactor() throws IOException{
        serverSocket = ServerSocketChannel.open();
        selector = Selector.open(); 
        serverSocket.configureBlocking(false); 
        serverSocket.bind(new InetSocketAddress("127.0.0.1", 8080)); // 绑定监听 ip 与 port
        SelectionKey sk = serverSocket.register(selector, SelectionKey.OP_ACCEPT); // 将监听通道注册到 selector 选择器上
        sk.attach(new AcceptorHandler()); // selectionKey 绑定接受请求 handler处理器
    }
  
    @Override
    public void run() {
        try {
            while (!Thread.interrupted()) {
                selector.select(); // 阻塞，直到有通道准备就绪 or 该 selector 的 wakeup 方法被 invoke or the current thread is interrupted
                Set<SelectionKey> selected = selector.selectedKeys(); // 获取通道准备就绪的 selectionKey
                Iterator<SelectionKey> it = selected.iterator();
                while (it.hasNext()) {
                    SelectionKey sk = it.next();
                    dispatch(sk);
                }
                selected.clear();
            }
        }catch (IOException ex) {
            ex.printStackTrace();
        }
    }
  
    private void dispatch(SelectionKey sk) {
        Runnable handler = (Runnable) sk.attachment(); // 获取绑定在 selectionKey 选择键上的 handler 处理器
        if(handler != null) {
            handler.run();
        }
    }
    
    class AcceptorHandler implements Runnable {
        @Override
        public void run() {
            try {
                SocketChannel socketChannel = serverSocket.accept();
                if(socketChannel !=null) {
                    new EchoHandler(selector, socketChannel);
                }
            }catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    }
  
    public static void main(String[] args) throws IOException{
        new Thread(new EchoServerReactor()).start();
    }
  }
  

多线程 Reactor 模式

示例代码

• MultiThreadEchoServeReactor.java 回显服务器

  package com.netty.im.Reactor.mutilThread;
  import java.io.IOException;
  import java.net.InetSocketAddress;
  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;
  import java.util.concurrent.atomic.AtomicInteger;
  /**
   * Created by andy on 2020/8/21.
   */
  public class MultiThreadEchoServeReactor {
    ServerSocketChannel serverSocket;
    AtomicInteger next = new AtomicInteger(0);
    Selector[] selectors = new Selector[2];
    SubReactor[] subReactors;
  
    MultiThreadEchoServeReactor() throws IOException {
        selectors[0] = Selector.open();
        selectors[1] = Selector.open();
        InetSocketAddress address = new InetSocketAddress("127.0.0.1", 8080);
        serverSocket.socket().bind(address);
        serverSocket.configureBlocking(false);
        SelectionKey sk = serverSocket.register(selectors[0], SelectionKey.OP_ACCEPT);
        sk.attach(new AcceptHandler());
  
        SubReactor subReactor1 = new SubReactor(selectors[0]);
        SubReactor subReactor2 = new SubReactor(selectors[1]);
        subReactors = new SubReactor[]{subReactor1, subReactor2};
    }
  
    private void startService() {
        new Thread(subReactors[0]).start();
        new Thread(subReactors[1]).start();
    }
  
    private void dispatch(SelectionKey sk) {
        Runnable handle = (Runnable) sk.attachment();
        if(null != handle) {
            handle.run();
        }
    }
  
    class AcceptHandler implements Runnable {
        @Override
        public void run() {
            try {
                SocketChannel channel = serverSocket.accept();
                if(channel != null) {
                    // 绑定 handler
                    new MultiThreadEchoHandler(selectors[next.get()], channel);
                }
            }catch (IOException ex) {
                ex.printStackTrace();
            }
            if(next.incrementAndGet() == selectors.length) {
                next.set(0);
            }
        }
    }
    
    class SubReactor implements Runnable {
  
        private Selector selector;
        SubReactor(Selector selector) {
            this.selector = selector;
        }
        @Override
        public void run() {
            try {
                while (!Thread.interrupted()) {
                    selector.select();
                    Set<SelectionKey> selectedKeys = selector.selectedKeys();
                    Iterator<SelectionKey> it = selectedKeys.iterator();
                    while (it.hasNext()) {
                        SelectionKey sk = it .next();
                        dispatch(sk);
                    }                }
            }catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    }
  }