NIO文章之一個線程同時監聽2個socket

首先，創建服務端類，代碼如下

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.nio.channels.spi.SelectorProvider;
import java.util.Iterator;


/**
 * 測試一個線程監聽兩個socket的類
 * @author andy
 *
 */
public class ServerDemo  implements Runnable{
	
	private int port1 = 8099;//端口
	private int port2 = 8088;
	
	private ServerSocketChannel serversocketchannel1;//服務器通道
	private ServerSocketChannel serversocketchannel2;
	
	private SocketChannel socketChannel1;//連接
	private SocketChannel socketChannel2;
	
	private Selector selector;//選擇器
	
	private ByteBuffer byteBuffer = ByteBuffer.allocate(512);//緩衝區
	
	public ServerDemo() {
		init();
	}

	
	@Override
	public void run() {
		
		while(true) {
			
			try{
				System.out.println("thread is runing ……");
				selector.select();
				Iterator selectorkeys = selector.selectedKeys().iterator();
				while(selectorkeys.hasNext()) {
					SelectionKey key = (SelectionKey) selectorkeys.next();
					selectorkeys.remove();
					if(!key.isValid()) {
						continue;
					}
					if(key.isAcceptable()) {
						accept(key);
					} else if(key.isReadable()) {
						read(key);
					}
				}
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
	}
	
	/**
	 * 初始化測試類
	 * 1.初始化選擇器
	 * 2.打開兩個通道
	 * 3.給通道上綁定一個socket
	 * 4.將選擇器註冊到通道上
	 */
	public void init() {
		try{
			selector = SelectorProvider.provider().openSelector();//創建選擇器
			
			//初始化第一個服務端
			serversocketchannel1 = ServerSocketChannel.open();//打開第一個通道
			serversocketchannel1.configureBlocking(false);//設置非阻塞方式
			serversocketchannel1.socket().bind(new InetSocketAddress("localhost",port1));
			serversocketchannel1.register(selector, SelectionKey.OP_ACCEPT);
			
			
			//初始化第二個服務端
			serversocketchannel2 = ServerSocketChannel.open();
			serversocketchannel2.configureBlocking(false);
			serversocketchannel2.socket().bind(new InetSocketAddress("localhost",port2));
			serversocketchannel2.register(selector, SelectionKey.OP_ACCEPT);
			
			
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	/**
	 * 客戶端連接服務器
	 * @param key
	 */
	public void accept(SelectionKey key) {
		
		ServerSocketChannel channel = (ServerSocketChannel) key.channel();
		try{
			if(channel.equals(serversocketchannel1)) {
				socketChannel1 = channel.accept();
				socketChannel1.configureBlocking(false);
				socketChannel1.register(selector, SelectionKey.OP_READ);
			} else {
				socketChannel2 = channel.accept();
				socketChannel2.configureBlocking(false);
				socketChannel2.register(selector, SelectionKey.OP_READ);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		
	}
	
	/**
	 * 從通道中讀取數據
	 * @param key
	 */
	public void read(SelectionKey key) {
		this.byteBuffer.clear();//清空緩存
		SocketChannel channel = (SocketChannel) key.channel();
		try {
			int count = channel.read(byteBuffer);
			if(count == -1) {
				key.channel().close();
				key.cancel();
				return;
			}
			//從緩衝區中取數據
			String input = new String(byteBuffer.array()).trim();
			if(channel.equals(socketChannel1)) {
				System.out.println("歡迎使用服務器1！");
				System.out.println("信息：" + input);
			} else {
				System.out.println("歡迎使用服務器2！");
				System.out.println("信息：" + input);
			}
		} catch (IOException e) {
			
			e.printStackTrace();
		}
		
	}
	
	public static void main(String[] args) {
		ServerDemo serverDemo = new ServerDemo();
		Thread thread = new Thread(serverDemo);
		thread.start();
	}
}

再創建客戶端類，代碼如下：

import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;


public class ClientDemo {

	private ByteBuffer buffer = ByteBuffer.allocate(512);//創建一個緩衝區
	
	public void query(String host,int port) {
		try {
			InetSocketAddress address = new InetSocketAddress(InetAddress.getByName(host), port);
			SocketChannel channel = null;
			byte[] bytes = new byte[512];
			
			while(true) {
				try{
					System.in.read(bytes);
					channel = SocketChannel.open();
					channel.connect(address);
					buffer.clear();
					buffer.put(bytes);
					buffer.flip();
					channel.write(buffer);
					buffer.clear();
					
				} catch(Exception e ) {
					e.printStackTrace();
				} finally {
					if(channel != null) {
						try {
							channel.close();
						} catch (IOException e) {
							e.printStackTrace();
						}
					}
				}
			}
		} catch (UnknownHostException e) {
			e.printStackTrace();
		}
	}
	public static void main(String[] args) {
		new ClientDemo().query("localhost", 8099);
		new ClientDemo().query("localhost", 8088);
	}
}

測試的時候，首先運行服務端類，再運行客戶端類。

在客戶端控制檯上可以直接輸入內容 按回車鍵之後，切換到服務端的控制檯。就能收到服務端打印出來的消息