JavaNetty

Netty的简单使用：

import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;

public class Client {

	public static void main(String[] args) throws Exception{

		EventLoopGroup group = new NioEventLoopGroup();
		Bootstrap b = new Bootstrap();
		b.group(group)
		.channel(NioSocketChannel.class)
		.handler(new ChannelInitializer<SocketChannel>() {
			@Override
			protected void initChannel(SocketChannel sc) throws Exception {
				sc.pipeline().addLast(new ClientHandler());
			}
		});

		ChannelFuture cf1 = b.connect("127.0.0.1", 8765).sync();
		//ChannelFuture cf2 = b.connect("127.0.0.1", 8764).sync();
		//发送消息
		Thread.sleep(1000);

		cf1.channel().writeAndFlush(Unpooled.copiedBuffer("777".getBytes()));
		cf1.channel().writeAndFlush(Unpooled.copiedBuffer("666".getBytes()));
		//cf2.channel().writeAndFlush(Unpooled.copiedBuffer("888".getBytes()));
		Thread.sleep(2000);
		cf1.channel().writeAndFlush(Unpooled.copiedBuffer("888".getBytes()));
		//cf2.channel().writeAndFlush(Unpooled.copiedBuffer("666".getBytes()));

		cf1.channel().closeFuture().sync();
		//cf2.channel().closeFuture().sync();
		group.shutdownGracefully();
	}
}

　　

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;

public class Server {

	public static void main(String[] args) throws Exception {
		//1 创建线两个程组
		//一个是用于处理服务器端接收客户端连接的
		//一个是进行网络通信的（网络读写的）
		EventLoopGroup pGroup = new NioEventLoopGroup();
		EventLoopGroup cGroup = new NioEventLoopGroup();

		//2 创建辅助工具类，用于服务器通道的一系列配置
		ServerBootstrap b = new ServerBootstrap();
		b.group(pGroup, cGroup)		//绑定俩个线程组
		.channel(NioServerSocketChannel.class)		//指定NIO的模式
		.option(ChannelOption.SO_BACKLOG, 1024)		//设置tcp缓冲区
		.option(ChannelOption.SO_SNDBUF, 32*1024)	//设置发送缓冲大小
		.option(ChannelOption.SO_RCVBUF, 32*1024)	//这是接收缓冲大小
		.option(ChannelOption.SO_KEEPALIVE, true)	//保持连接
		.childHandler(new ChannelInitializer<SocketChannel>() {
			@Override
			protected void initChannel(SocketChannel sc) throws Exception {
				//3 在这里配置具体数据接收方法的处理
				sc.pipeline().addLast(new ServerHandler());
			}
		});

		//4 进行绑定
		ChannelFuture cf1 = b.bind(8765).sync();
		//ChannelFuture cf2 = b.bind(8764).sync();
		//5 等待关闭
		cf1.channel().closeFuture().sync();
		//cf2.channel().closeFuture().sync();
		pGroup.shutdownGracefully();
		cGroup.shutdownGracefully();
	}
}

　　

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;

public class ServerHandler extends ChannelHandlerAdapter {

	@Override
	public void channelActive(ChannelHandlerContext ctx) throws Exception {
		System.out.println("server channel active... ");
	}

	@Override
	public void channelRead(ChannelHandlerContext ctx, Object msg)
			throws Exception {
			ByteBuf buf = (ByteBuf) msg;
			byte[] req = new byte[buf.readableBytes()];
			buf.readBytes(req);
			String body = new String(req, "utf-8");
			System.out.println("Server :" + body );
			String response = "进行返回给客户端的响应：" + body ;
			ctx.writeAndFlush(Unpooled.copiedBuffer(response.getBytes()));
			//.addListener(ChannelFutureListener.CLOSE);
	}

	@Override
	public void channelReadComplete(ChannelHandlerContext ctx)
			throws Exception {
		System.out.println("读完了");
		ctx.flush();
	}

	@Override
	public void exceptionCaught(ChannelHandlerContext ctx, Throwable t)
			throws Exception {
		ctx.close();
	}
}

　　

aio代码：

import java.net.InetSocketAddress;
import java.nio.channels.AsynchronousChannelGroup;
import java.nio.channels.AsynchronousServerSocketChannel;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class Server {
	//线程池
	private ExecutorService executorService;
	//线程组
	private AsynchronousChannelGroup threadGroup;
	//服务器通道
	public AsynchronousServerSocketChannel assc;

	public Server(int port){
		try {
			//创建一个缓存池
			executorService = Executors.newCachedThreadPool();
			//创建线程组
			threadGroup = AsynchronousChannelGroup.withCachedThreadPool(executorService, 1);
			//创建服务器通道
			assc = AsynchronousServerSocketChannel.open(threadGroup);
			//进行绑定
			assc.bind(new InetSocketAddress(port));

			System.out.println("server start , port : " + port);
			//进行阻塞
			assc.accept(this, new ServerCompletionHandler());
			//一直阻塞 不让服务器停止
			Thread.sleep(Integer.MAX_VALUE);

		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public static void main(String[] args) {
		Server server = new Server(8765);
	}

}

　　

import java.io.UnsupportedEncodingException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.util.concurrent.ExecutionException;

public class Client implements Runnable{

	private AsynchronousSocketChannel asc ;

	public Client() throws Exception {
		asc = AsynchronousSocketChannel.open();
	}

	public void connect(){
		asc.connect(new InetSocketAddress("127.0.0.1", 8765));
	}

	public void write(String request){
		try {
			asc.write(ByteBuffer.wrap(request.getBytes())).get();
			read();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	private void read() {
		ByteBuffer buf = ByteBuffer.allocate(1024);
		try {
			asc.read(buf).get();
			buf.flip();
			byte[] respByte = new byte[buf.remaining()];
			buf.get(respByte);
			System.out.println(new String(respByte,"utf-8").trim());
		} catch (InterruptedException e) {
			e.printStackTrace();
		} catch (ExecutionException e) {
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
	}

	@Override
	public void run() {
		while(true){

		}
	}

	public static void main(String[] args) throws Exception {
		Client c1 = new Client();
		c1.connect();

		Client c2 = new Client();
		c2.connect();

		Client c3 = new Client();
		c3.connect();

		new Thread(c1, "c1").start();
		new Thread(c2, "c2").start();
		new Thread(c3, "c3").start();

		Thread.sleep(1000);

		c1.write("c1 aaa");
		c2.write("c2 bbbb");
		c3.write("c3 ccccc");
	}
}

　　

import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;
import java.util.concurrent.ExecutionException;

public class ServerCompletionHandler implements CompletionHandler<AsynchronousSocketChannel, Server> {

	@Override
	public void completed(AsynchronousSocketChannel asc, Server attachment) {
		//当有下一个客户端接入的时候 直接调用Server的accept方法，这样反复执行下去，保证多个客户端都可以阻塞
		attachment.assc.accept(attachment, this);
		read(asc);
	}

	private void read(final AsynchronousSocketChannel asc) {
		//读取数据
		ByteBuffer buf = ByteBuffer.allocate(1024);
		asc.read(buf, buf, new CompletionHandler<Integer, ByteBuffer>() {
			@Override
			public void completed(Integer resultSize, ByteBuffer attachment) {
				//进行读取之后,重置标识位
				attachment.flip();
				//获得读取的字节数
				System.out.println("Server -> " + "收到客户端的数据长度为:" + resultSize);
				//获取读取的数据
				String resultData = new String(attachment.array()).trim();
				System.out.println("Server -> " + "收到客户端的数据信息为:" + resultData);
				String response = "服务器响应, 收到了客户端发来的数据: " + resultData;
				write(asc, response);
			}
			@Override
			public void failed(Throwable exc, ByteBuffer attachment) {
				exc.printStackTrace();
			}
		});
	}

	private void write(AsynchronousSocketChannel asc, String response) {
		try {
			ByteBuffer buf = ByteBuffer.allocate(1024);
			buf.put(response.getBytes());
			buf.flip();
			asc.write(buf).get();
		} catch (InterruptedException e) {
			e.printStackTrace();
		} catch (ExecutionException e) {
			e.printStackTrace();
		}
	}

	@Override
	public void failed(Throwable exc, Server attachment) {
		exc.printStackTrace();
	}

}

　　bio：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

public class Client {

	final static String ADDRESS = "127.0.0.1";
	final static int PORT = 8765;

	public static void main(String[] args) {

		Socket socket = null;
		BufferedReader in = null;
		PrintWriter out = null;

		try {
			socket = new Socket(ADDRESS, PORT);
			in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
			out = new PrintWriter(socket.getOutputStream(), true);

			//向服务器端发送数据
			out.println("接收到客户端的请求数据...");
			String response = in.readLine();
			System.out.println("Client: " + response);

		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if(in != null){
				try {
					in.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			if(out != null){
				try {
					out.close();
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
			if(socket != null){
				try {
					socket.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			socket = null;
		}
	}
}

　

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {

	final static int PROT = 8765;

	public static void main(String[] args) {

		ServerSocket server = null;
		try {
			server = new ServerSocket(PROT);
			System.out.println(" server start .. ");
			//进行阻塞
			Socket socket = server.accept();
			//新建一个线程执行客户端的任务
			new Thread(new ServerHandler(socket)).start();

		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if(server != null){
				try {
					server.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			server = null;
		}

	}
}

　　

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

public class ServerHandler implements Runnable{

	private Socket socket ;

	public ServerHandler(Socket socket){
		this.socket = socket;
	}

	@Override
	public void run() {
		BufferedReader in = null;
		PrintWriter out = null;
		try {
			in = new BufferedReader(new InputStreamReader(this.socket.getInputStream()));
			out = new PrintWriter(this.socket.getOutputStream(), true);
			String body = null;
			while(true){
				body = in.readLine();
				if(body == null) break;
				System.out.println("Server :" + body);
				out.println("服务器端回送响的应数据.");
			}

		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if(in != null){
				try {
					in.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			if(out != null){
				try {
					out.close();
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
			if(socket != null){
				try {
					socket.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			socket = null;
		}
	}
}

　　nio：

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

public class Client {

	//需要一个Selector
	public static void main(String[] args) {

		//创建连接的地址
		InetSocketAddress address = new InetSocketAddress("127.0.0.1", 8765);

		//声明连接通道
		SocketChannel sc = null;

		//建立缓冲区
		ByteBuffer buf = ByteBuffer.allocate(1024);

		try {
			//打开通道
			sc = SocketChannel.open();
			//进行连接
			sc.connect(address);

			while(true){
				//定义一个字节数组，然后使用系统录入功能：
				byte[] bytes = new byte[1024];
				System.in.read(bytes);

				//把数据放到缓冲区中
				buf.put(bytes);
				//对缓冲区进行复位
				buf.flip();
				//写出数据
				sc.write(buf);
				//清空缓冲区数据
				buf.clear();
			}
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			if(sc != null){
				try {
					sc.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}

	}
}

　　

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;

public class Server implements Runnable{
	//1 多路复用器（管理所有的通道）
	private Selector seletor;
	//2 建立缓冲区
	private ByteBuffer readBuf = ByteBuffer.allocate(1024);
	//3
	private ByteBuffer writeBuf = ByteBuffer.allocate(1024);
	public Server(int port){
		try {
			//1 打开路复用器
			this.seletor = Selector.open();
			//2 打开服务器通道
			ServerSocketChannel ssc = ServerSocketChannel.open();
			//3 设置服务器通道为非阻塞模式
			ssc.configureBlocking(false);
			//4 绑定地址
			ssc.bind(new InetSocketAddress(port));
			//5 把服务器通道注册到多路复用器上，并且监听阻塞事件
			ssc.register(this.seletor, SelectionKey.OP_ACCEPT);

			System.out.println("Server start, port :" + port);

		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	@Override
	public void run() {
		while(true){
			try {
				//1 必须要让多路复用器开始监听
				this.seletor.select();
				//2 返回多路复用器已经选择的结果集
				Iterator<SelectionKey> keys = this.seletor.selectedKeys().iterator();
				//3 进行遍历
				while(keys.hasNext()){
					//4 获取一个选择的元素
					SelectionKey key = keys.next();
					//5 直接从容器中移除就可以了
					keys.remove();
					//6 如果是有效的
					if(key.isValid()){
						//7 如果为阻塞状态
						if(key.isAcceptable()){
							this.accept(key);
						}
						//8 如果为可读状态
						if(key.isReadable()){
							this.read(key);
						}
						//9 写数据
						if(key.isWritable()){
							//this.write(key); //ssc
						}
					}

				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

	private void write(SelectionKey key){
		//ServerSocketChannel ssc =  (ServerSocketChannel) key.channel();
		//ssc.register(this.seletor, SelectionKey.OP_WRITE);
	}

	private void read(SelectionKey key) {
		try {
			//1 清空缓冲区旧的数据
			this.readBuf.clear();
			//2 获取之前注册的socket通道对象
			SocketChannel sc = (SocketChannel) key.channel();
			//3 读取数据
			int count = sc.read(this.readBuf);
			//4 如果没有数据
			if(count == -1){
				key.channel().close();
				key.cancel();
				return;
			}
			//5 有数据则进行读取 读取之前需要进行复位方法(把position 和limit进行复位)
			this.readBuf.flip();
			//6 根据缓冲区的数据长度创建相应大小的byte数组，接收缓冲区的数据
			byte[] bytes = new byte[this.readBuf.remaining()];
			//7 接收缓冲区数据
			this.readBuf.get(bytes);
			//8 打印结果
			String body = new String(bytes).trim();
			System.out.println("Server : " + body);

			// 9..可以写回给客户端数据 

		} catch (IOException e) {
			e.printStackTrace();
		}

	}

	private void accept(SelectionKey key) {
		try {
			//1 获取服务通道
			ServerSocketChannel ssc =  (ServerSocketChannel) key.channel();
			//2 执行阻塞方法
			SocketChannel sc = ssc.accept();
			//3 设置阻塞模式
			sc.configureBlocking(false);
			//4 注册到多路复用器上，并设置读取标识
			sc.register(this.seletor, SelectionKey.OP_READ);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	public static void main(String[] args) {

		new Thread(new Server(8765)).start();;
	}
}

　　

import java.nio.IntBuffer;

public class TestBuffer {

	public static void main(String[] args) {

		// 1 基本操作

		//创建指定长度的缓冲区
		IntBuffer buf = IntBuffer.allocate(10);
		buf.put(13);// position位置：0 - > 1
		buf.put(21);// position位置：1 - > 2
		buf.put(35);// position位置：2 - > 3
		//把位置复位为0，也就是position位置：3 - > 0
		buf.flip();
		System.out.println("使用flip复位：" + buf);
		System.out.println("容量为: " + buf.capacity());	//容量一旦初始化后不允许改变（warp方法包裹数组除外）
		System.out.println("限制为: " + buf.limit());		//由于只装载了三个元素,所以可读取或者操作的元素为3 则limit=3

		System.out.println("获取下标为1的元素：" + buf.get(1));
		System.out.println("get(index)方法，position位置不改变：" + buf);
		buf.put(1, 4);
		System.out.println("put(index, change)方法，position位置不变：" + buf);;

		for (int i = 0; i < buf.limit(); i++) {
			//调用get方法会使其缓冲区位置（position）向后递增一位
			System.out.print(buf.get() + "\t");
		}
		System.out.println("buf对象遍历之后为: " + buf);

		// 2 wrap方法使用

		//  wrap方法会包裹一个数组: 一般这种用法不会先初始化缓存对象的长度，因为没有意义，最后还会被wrap所包裹的数组覆盖掉。
		//  并且wrap方法修改缓冲区对象的时候，数组本身也会跟着发生变化。
		int[] arr = new int[]{1,2,5};
		IntBuffer buf1 = IntBuffer.wrap(arr);
		System.out.println(buf1);

		IntBuffer buf2 = IntBuffer.wrap(arr, 0 , 2);
		//这样使用表示容量为数组arr的长度，但是可操作的元素只有实际进入缓存区的元素长度
		System.out.println(buf2);

		// 3 其他方法

		IntBuffer buf1 = IntBuffer.allocate(10);
		int[] arr = new int[]{1,2,5};
		buf1.put(arr);
		System.out.println(buf1);
		//一种复制方法
		IntBuffer buf3 = buf1.duplicate();
		System.out.println(buf3);

		//设置buf1的位置属性
		//buf1.position(0);
		buf1.flip();
		System.out.println(buf1);

		System.out.println("可读数据为：" + buf1.remaining());

		int[] arr2 = new int[buf1.remaining()];
		//将缓冲区数据放入arr2数组中去
		buf1.get(arr2);
		for(int i : arr2){
			System.out.print(Integer.toString(i) + ",");
		}
	}
}