网络编程之NIO聊天室

1.创建Nio服务端

package nio.study;

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

import javax.xml.ws.handler.MessageContext.Scope;

/**
 *创建Nio服务端 
 */
public class NIOServer {
    /**
     *启动 
     * @throws IOException 
     */
    public void start() throws IOException {
        /**
         * 1、 创建selector
         */
        Selector selector = Selector.open();
        
        /**
         * 2、通过ServerScoketChannel创建channel通过 
         */
        ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
        
        /**
         * 3、为channel通道绑定监听端口 
         */
        serverSocketChannel.bind(new InetSocketAddress(8000));
        /**
         * 4、**设置channel为非阻塞状态 
         */
        serverSocketChannel.configureBlocking(false);
        
        
        /**
         * 5、将channel注册到selector上 监听连接事件
         */
        serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
        System.out.println("服务器启动成功！");
        /**
         * 6、循环等待新接入的连接 
         */
        for(;;) {
            /**
             * TODO 获取可用channel数量
             */
            int readyChannels = selector.select();
            /**
             * TODO 为什么这样？
             */
            if(readyChannels == 0) continue;
            /**
             *获取channel可用集合 
             */
            Set selectedKeys = selector.selectedKeys();
            Iterator iterator = selectedKeys.iterator();
            while(iterator.hasNext()) {
                /**
                 *selectrionKey实例 
                 */
                SelectionKey selectionKey = iterator.next();
                /**
                 *移除Set中的当前selectionKey 
                 */
                iterator.remove();
                /**
                 * 7、根据就绪状态，调用对应方法处理业务逻辑 
                 */
                /**
                 *如果是接入事件 
                 */
                if(selectionKey.isAcceptable()) {
                    acceptHandler(serverSocketChannel, selector);
                }
                /**
                 *如果是可读事件 
                 */
                if(selectionKey.isReadable()) {
                    readHandler(selectionKey, selector);
                }
            }
            
        }
    }
    /**
     *接入事件处理 
     * @throws IOException 
     */
    private void acceptHandler(ServerSocketChannel serverSocketChannel,Selector selector) 
            throws IOException {
        /**
         *如果是接入事件，创建socketChannel 
         */
        SocketChannel socketChannel = serverSocketChannel.accept();
        /**
         *将socketChannel设置为非阻塞工作模式 
         */
        socketChannel.configureBlocking(false);
        /**
         *将channel注册到selector上，监听可读事件 
         */
        socketChannel.register(selector, SelectionKey.OP_READ);
        /**
         * 回写客户端提示信息
         */
        socketChannel.write(Charset.forName("UTF-8").
                encode("你与聊天室的其他人都不是朋友关系，请注意隐私安全"));
    }
    /**
     *可读事件处理 
     * @throws IOException 
     */
    private void readHandler(SelectionKey selectionKey,Selector selector) throws IOException {
        /**
         *要从 selectionKey中获取已经就绪的channe 
         *SocketChannel socketChannel = (SocketChannel)selectionKey.channel();
         */
        SocketChannel socketChannel = (SocketChannel)selectionKey.channel();
         /**
          * 创建Buffer
          */
         ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
         /**
          *循环读取客户端信息 
          */
         String request = "";
         while(socketChannel.read(byteBuffer)>0) {
             /**
              *切换buffer为读模式 
              */
             byteBuffer.flip();
             /**
              *读取buffer中的内容 
              */
             request += Charset.forName("UTF-8").decode(byteBuffer);
         }
         /**
          * 再次将socketChannel注册到selector上
          */
         socketChannel.register(selector, SelectionKey.OP_READ);
         /**
          * 将客户端发送的请求信息，广播给其他客户端
          */
         if(request.length() > 0) {
             broadCast(selector, socketChannel, request);
         }
    }
    
    private void broadCast(Selector selector,SocketChannel sourceChannel,String request) {
        /**
         *获取到所有已接入的客户端channel 
         */
        Set selectionKeySet = selector.keys();
        /**
         *循环向所有channel广播 
         */
        selectionKeySet.forEach(selectionKey->{
            Channel targetchannel = selectionKey.channel();
            //剔除发消息的客户端
            if(targetchannel instanceof SocketChannel
                    && targetchannel != sourceChannel) {
                try {
                    ((SocketChannel)targetchannel).
                    write(Charset.forName("UTF-8").encode(request));
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        });
    }
    /**
     *主方法 
     * @throws IOException 
     */
    public static void main(String[] args) throws IOException {
        NIOServer server = new NIOServer();
        server.start();
    }
}

2、创建NIO客户端

package nio.study;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;
import java.util.Scanner;

public class NioClient {
    /**
     *启动 
     * @throws IOException 
     */
    public void start(String nickName) throws IOException {
        /**
         *连接服务器端 
         */
        SocketChannel socketChannel = SocketChannel.open(new InetSocketAddress("127.0.0.1", 8000));
        /**
         *接收服务端的响应 
         */
        //新开线程专门接收服务器端的响应数据
        Selector selector = Selector.open();
        socketChannel.configureBlocking(false);
        socketChannel.register(selector, SelectionKey.OP_READ);
        new Thread(new NioClientThreadHandler(selector)).start();;
        
        /**
         *向服务器发送数据
         */
        System.out.println("客户端：");
        Scanner scanner = new Scanner(System.in);
        while(scanner.hasNextLine()) {
            String request = scanner.nextLine();
            if(request != null && request.length() > 0) {
                socketChannel.write(Charset.forName("UTF-8").encode(nickName+":"+request));
            }
        }
        
    }
    /**
     *主方法 
     * @throws IOException 
     */
    public static void main(String[] args) throws IOException {
//      new NioClient().start();
    }
}

3、NIO客户端线程处理类

package nio.study;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;
import java.util.Iterator;
import java.util.Set;

public class NioClientThreadHandler implements Runnable {
    private Selector selector;
    
    public NioClientThreadHandler(Selector selector) {
        super();
        this.selector = selector;
    }

    @Override
    public void run() {
         for(;;) {
             try {
                int readyChannels = selector.select();
            
                if(readyChannels == 0) continue;
                /**
                 *获取channel可用集合 
                 */
                Set selectedKeys = selector.selectedKeys();
                Iterator iterator = selectedKeys.iterator();
                while(iterator.hasNext()) {
                    /**
                     *selectrionKey实例 
                     */
                    SelectionKey selectionKey = iterator.next();
                    /**
                     *移除Set中的当前selectionKey 
                     */
                    iterator.remove();
                     
                    /**
                     *如果是接入事件 
                     */
                    if(selectionKey.isReadable()) {
                        readHandler(selectionKey, selector);
                    }
                    
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
         }
        
    }
    private void readHandler(SelectionKey selectionKey,Selector selector) throws IOException {
        /**
         *要从 selectionKey中获取已经就绪的channe 
         *SocketChannel socketChannel = (SocketChannel)selectionKey.channel();
         */
        SocketChannel socketChannel = (SocketChannel)selectionKey.channel();
         /**
          * 创建Buffer
          */
         ByteBuffer byteBuffer = ByteBuffer.allocate(1024);
         /**
          *循环读取客户端信息 
          */
         String response = "";
         while(socketChannel.read(byteBuffer)>0) {
             /**
              *切换buffer为读模式 
              */
             byteBuffer.flip();
             /**
              *读取buffer中的内容 
              */
             response += Charset.forName("UTF-8").decode(byteBuffer);
         }
         /**
          * 再次将socketChannel注册到selector上
          */
         socketChannel.register(selector, SelectionKey.OP_READ);
         /**
          * 将服务的信息
          */
         if(response.length() > 0) {
             System.out.println(response);
         }
    }

}

4、创建NioClient多个客户端实现聊天

package nio.study;

import java.io.IOException;

public class AClient {
    public static void main(String[] args) throws IOException {
        new NioClient().start("AClient");
    }
}
package nio.study;

import java.io.IOException;

public class BClient {
    public static void main(String[] args) throws IOException {
        new NioClient().start("BClient");
    }
}
package nio.study;

import java.io.IOException;

public class CClient {
    public static void main(String[] args) throws IOException {
        new NioClient().start("CClient");
    }
}