NIO-TCP简单实例

Java Nio系列教程；http://www.iteye.com/magazines/132-Java-NIO
Channel接口定义：http://donald-draper.iteye.com/blog/2369111
AbstractInterruptibleChannel接口定义：http://donald-draper.iteye.com/blog/2369238
SelectableChannel接口定义:http://donald-draper.iteye.com/blog/2369317
SelectionKey定义：http://donald-draper.iteye.com/blog/2369499
SelectorProvider定义：http://donald-draper.iteye.com/blog/2369615
AbstractSelectableChannel定义：http://donald-draper.iteye.com/blog/2369742
NetworkChannel接口定义：http://donald-draper.iteye.com/blog/2369773
ServerSocketChannel定义：http://donald-draper.iteye.com/blog/2369836
ServerSocketChannelImpl解析：http://donald-draper.iteye.com/blog/2370912
Selector定义：http://donald-draper.iteye.com/blog/2370015
AbstractSelector定义：http://donald-draper.iteye.com/blog/2370138
SelectorImpl分析 :http://donald-draper.iteye.com/blog/2370519
WindowsSelectorImpl解析一（FdMap，PollArrayWrapper）：
http://donald-draper.iteye.com/blog/2370811
WindowsSelectorImpl解析二（选择操作，通道注册，通道反注册，选择器关闭等）：
http://donald-draper.iteye.com/blog/2370862
SocketChannel接口定义:http://donald-draper.iteye.com/blog/2371218
SocketChannelImpl 解析一（通道连接，发送数据）：http://donald-draper.iteye.com/blog/2372364
SocketChannelImpl 解析二（发送数据后续）：http://donald-draper.iteye.com/blog/2372548
SocketChannelImpl 解析三（接收数据）：http://donald-draper.iteye.com/blog/2372590
SocketChannelImpl 解析四（关闭通道等） ：http://donald-draper.iteye.com/blog/2372717
MembershipKey定义:http://donald-draper.iteye.com/blog/2372947
MulticastChanne接口定义：http://donald-draper.iteye.com/blog/2373009
MembershipKeyImpl 简介：http://donald-draper.iteye.com/blog/2373066
DatagramChannel定义：http://donald-draper.iteye.com/blog/2373046
DatagramChannelImpl 解析一（初始化）：http://donald-draper.iteye.com/blog/2373245
DatagramChannelImpl 解析二（报文发送与接收）：http://donald-draper.iteye.com/blog/2373281
DatagramChannelImpl 解析三（多播）：http://donald-draper.iteye.com/blog/2373507
DatagramChannelImpl 解析四（地址绑定，关闭通道等）：http://donald-draper.iteye.com/blog/2373519
     Java Nio从JDK1.4之后，才加入到JDK中，在JDK1.1之后，1.4之前，网络编程一般用阻塞BIO，NIO为非阻的IO，NIO主要包括Selector，Channel（Tcp:ServerSocket，Socket;
Udp:Datagram,File;Pipe:Sink，Source），Buffer，SelectionKey等相关的概念在网上有很多这里就不说了，今天文章我们用NIO写一个基于TCP的简单Server和Client。TCP在NIO主要基于ServerSocketChannel和ServerChannel，下面来看实例。
服务端：

package nio.simplesocket;

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;

/**
 * Sever
 * @author donald
 * 2017年4月11日
 * 下午9:24:03
 */
public class NIOServer {
	//manager the channel
	private Selector selector;
	/**
	 * stat Server
	 * @param args
	 * @throws IOException
	 */
	public static void main(String[] args) throws IOException{
		NIOServer server = new NIOServer();
		server.initServer("192.168.32.126", 10000);
		server.listen();
	}
	/**
	 * get the ServerSocket and finish some initial work
	 * @param port
	 * @throws IOException
	 */
	public void initServer(String host, int port) throws IOException{
		//get the ServerSocket
		ServerSocketChannel serverChannel = ServerSocketChannel.open();
		// set no blocking mode
		serverChannel.configureBlocking(false);
		//bind the port
		serverChannel.socket().bind(new InetSocketAddress(host, port));
		//get the channel manager
		this.selector = Selector.open();
		//Register the channel to manager and bind the event
		serverChannel.register(selector,SelectionKey.OP_ACCEPT);
		}
	/**
	 * use asking mode to listen the event of selector
	 * @throws IOException 
	 */
	@SuppressWarnings("rawtypes")
	public void listen() throws IOException{
		System.out.println("=========The Server is start!===========");
		while(true){
			selector.select();
			Iterator ite =  this.selector.selectedKeys().iterator();
			while(ite.hasNext()){
				SelectionKey key = (SelectionKey)ite.next();
				ite.remove();
				if(key.isAcceptable()){
					ServerSocketChannel server = (ServerSocketChannel)key.channel();
					SocketChannel channel = server.accept();
					channel.configureBlocking(false);
					channel.write(ByteBuffer.wrap(new String("Hello client!").getBytes()));
					channel.register(this.selector, SelectionKey.OP_READ);
				}
				else if (key.isReadable()) read(key);
			}
			
		}
	}
	/**
	 * deal with the message come from the client
	 * @param key
	 * @throws IOException 
	 */
	public void read(SelectionKey key) throws IOException{
		SocketChannel channel = (SocketChannel) key.channel();
		ByteBuffer buf = ByteBuffer.allocate(100);
		channel.read(buf);
		byte[] data = buf.array();
		String msg = new String(data).trim();
		System.out.println("message come from client:"+msg);
	}
	
}

客户端：

package nio.simplesocket;

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.SocketChannel;
import java.util.Iterator;

/**
 * Client
 * @author donald
 * 2017年4月11日
 * 下午9:24:09
 */
public class NIOClient {
	//manager the channel
	private Selector selector;
	/**
	 * stat Client
	 * @param args
	 * @throws IOException
	 */
	public static void main(String[] args) throws IOException{
		NIOClient client = new NIOClient();
		client.initClient("192.168.32.126",10000);
		client.listen();
	}
	/**
	 * get the Socket and finish some initial work
	 * @param ip Server ip
	 * @param port connect Server port
	 * @throws IOException
	 */
	public void initClient(String ip,int port) throws IOException{
		//get the Socket
		SocketChannel channel = SocketChannel.open();
		// set no blocking mode
		channel.configureBlocking(false);
		//connect the Server
		channel.connect(new InetSocketAddress(ip,port));
		//get the channel manager
		this.selector = Selector.open();
		//Register the channel to manager and bind the event
		channel.register(selector,SelectionKey.OP_CONNECT);
		}
	/**
	 * use asking mode to listen the event of selector
	 * @throws IOException 
	 */
	@SuppressWarnings("rawtypes")
	public void listen() throws IOException{
		System.out.println("===========The Client is start!===========");
		while(true){
			selector.select();
			Iterator ite =  this.selector.selectedKeys().iterator();
			while(ite.hasNext()){
				SelectionKey key = (SelectionKey)ite.next();
				ite.remove();
				if(key.isConnectable()){
					SocketChannel channel = (SocketChannel)key.channel();
                    //during connecting, finish the connect
                    if(channel.isConnectionPending()){
                    	channel.finishConnect();
                    }
					channel.configureBlocking(false);
					channel.write(ByteBuffer.wrap(new String("Hello Server!").getBytes()));
					channel.register(this.selector, SelectionKey.OP_READ);
				}
				else if (key.isReadable()) read(key);
			}
			
		}
	}
	/**
	 * deal with the message come from the server
	 * @param key
	 * @throws IOException 
	 */
	public void read(SelectionKey key) throws IOException{
		SocketChannel channel = (SocketChannel) key.channel();
		ByteBuffer buf = ByteBuffer.allocate(100);
		channel.read(buf);
		byte[] data = buf.array();
		String msg = new String(data).trim();
		System.out.println("message come from server:"+msg);
	}	
}

先启动NIOServer，在启动NIOClient，控制台输出：
NIOServer：
=========The Server is start!===========
message come from client:Hello Server!

NIOClient：
===========The Client is start!===========
message come from server:Hello client!

附：测试Buffer

package nio;

import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
/**
 * 协议测试
 * @author donald
 * 2017年4月10日
 * 下午9:26:57
 */
public class testByteBuffer {
	public static void main(String[] args) {
		ByteBuffer[] proctols = null;//
		proctols = new ByteBuffer[2];
		ByteBuffer protocolBuffer = null;//协议编码
		protocolBuffer = ByteBuffer.allocate(6);
		try {
			System.out.println("ProtocolCode String length："+new String("300000").getBytes("UTF-8").length);
			protocolBuffer.put(new String("300000").getBytes("UTF-8"));
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
		System.out.println("ProtocolCode length："+protocolBuffer.position());
		proctols[0] = protocolBuffer;
		ByteBuffer dataBuffer = null;//操作数
		dataBuffer = ByteBuffer.allocate(8);
		dataBuffer.putInt(15);
		dataBuffer.putInt(6);
		System.out.println("data length："+dataBuffer.position());
		proctols[1] = dataBuffer;
//		protocolBuffer.compact();//针对数据太大，缓冲区一次装不完的情况
		protocolBuffer.clear();
		try {
			protocolBuffer.put(new String("300100").getBytes("UTF-8"));
			System.out.println("ProtocolCode length："+protocolBuffer.position());
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
//		dataBuffer.compact();
		dataBuffer.clear();
		dataBuffer.putInt(17);
		dataBuffer.putInt(8);
		System.out.println("data length："+dataBuffer.position());
	}
}