Netty4詳解二：開發第一個Netty應用程序

package NettyDemo.echo.server;

import io.netty.bootstrap.ServerBootstrap;
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.NioServerSocketChannel;
import java.net.InetSocketAddress;
import NettyDemo.echo.handler.EchoServerHandler;
public class EchoServer {
	private static final int port = 8080;
	public void start() throws InterruptedException {
		ServerBootstrap b = new ServerBootstrap();// 引導輔助程序
		EventLoopGroup group = new NioEventLoopGroup();// 通過nio方式來接收連接和處理連接
		try {
			b.group(group);
			b.channel(NioServerSocketChannel.class);// 設置nio類型的channel
			b.localAddress(new InetSocketAddress(port));// 設置監聽端口
			b.childHandler(new ChannelInitializer<SocketChannel>() {//有連接到達時會創建一個channel
						protected void initChannel(SocketChannel ch) throws Exception {
							// pipeline管理channel中的Handler，在channel隊列中添加一個handler來處理業務
							ch.pipeline().addLast("myHandler", new EchoServerHandler());
						}
					});
			ChannelFuture f = b.bind().sync();// 配置完成，開始綁定server，通過調用sync同步方法阻塞直到綁定成功
			System.out.println(EchoServer.class.getName() + " started and listen on " + f.channel().localAddress());
			f.channel().closeFuture().sync();// 應用程序會一直等待，直到channel關閉
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			group.shutdownGracefully().sync();//關閉EventLoopGroup，釋放掉所有資源包括創建的線程
		}
	}
	public static void main(String[] args) {
		try {
			new EchoServer().start();
		} catch (InterruptedException e) {
			e.printStackTrace();
		}
	}
}

1. 連接到Server
2. 向Server寫數據
3. 等待Server返回數據
4. 關閉連接

package NettyDemo.echo.client;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
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;

import java.net.InetSocketAddress;

import NettyDemo.echo.handler.EchoClientHandler;

public class EchoClient {
	private final String host;
	private final int port;

	public EchoClient(String host, int port) {
		this.host = host;
		this.port = port;
	}

	public void start() throws Exception {
		EventLoopGroup group = new NioEventLoopGroup();
		try {
			Bootstrap b = new Bootstrap();
			b.group(group);
			b.channel(NioSocketChannel.class);
			b.remoteAddress(new InetSocketAddress(host, port));
			b.handler(new ChannelInitializer<SocketChannel>() {

				public void initChannel(SocketChannel ch) throws Exception {
					ch.pipeline().addLast(new EchoClientHandler());
				}
			});
			ChannelFuture f = b.connect().sync();
			f.addListener(new ChannelFutureListener() {
				
				public void operationComplete(ChannelFuture future) throws Exception {
					if(future.isSuccess()){
						System.out.println("client connected");
					}else{
						System.out.println("server attemp failed");
						future.cause().printStackTrace();
					}
					
				}
			});
			f.channel().closeFuture().sync();
		} finally {
			group.shutdownGracefully().sync();
		}
	}

	public static void main(String[] args) throws Exception {
	
		new EchoClient("127.0.0.1", 3331).start();
	}
}