netty权威指南之五 netty hello world

最近通过学习@李林峰 大神的 《netty权威指南》

对Java io 有了进一步的了解，我对其代码加了一些注解和个人的看法。

对netty有了进一步的了解，所以后面有一些对rocketmq和dubbo中协议部分的分析

还是那句话 学习使人进步  

netty  核心代码

EventLoopGroup bossGroup = new NioEventLoopGroup();
	EventLoopGroup workerGroup = new NioEventLoopGroup();
	try {
	    ServerBootstrap b = new ServerBootstrap();
	    b.group(bossGroup, workerGroup)
		    .channel(NioServerSocketChannel.class)
		    .option(ChannelOption.SO_BACKLOG, 1024)
		    .childHandler(new ChildChannelHandler());
	    // 绑定端口，同步等待成功
	    ChannelFuture f = b.bind(port).sync();

	    // 等待服务端监听端口关闭
	    f.channel().closeFuture().sync();
	} finally {
	    // 优雅退出，释放线程池资源
	    bossGroup.shutdownGracefully();
	    workerGroup.shutdownGracefully();
	}

/*
 * Copyright 2013-2018 Lilinfeng.
 *  
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.phei.netty.basic;

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;

/**
 * @author lilinfeng
 * @date 2014年2月14日
 * @version 1.0
 */
public class TimeServer {

    public void bind(int port) throws Exception {
	// 配置服务端的NIO线程组
	EventLoopGroup bossGroup = new NioEventLoopGroup();
	EventLoopGroup workerGroup = new NioEventLoopGroup();
	try {
	    ServerBootstrap b = new ServerBootstrap();
	    b.group(bossGroup, workerGroup)
		    .channel(NioServerSocketChannel.class)
		    .option(ChannelOption.SO_BACKLOG, 1024)
		    .childHandler(new ChildChannelHandler());
	    // 绑定端口，同步等待成功
	    ChannelFuture f = b.bind(port).sync();

	    // 等待服务端监听端口关闭
	    f.channel().closeFuture().sync();
	} finally {
	    // 优雅退出，释放线程池资源
	    bossGroup.shutdownGracefully();
	    workerGroup.shutdownGracefully();
	}
    }

    private class ChildChannelHandler extends ChannelInitializer<SocketChannel> {
	@Override
	protected void initChannel(SocketChannel arg0) throws Exception {
	    arg0.pipeline().addLast(new TimeServerHandler());
	}

    }

    /**
     * @param args
     * @throws Exception
     */
    public static void main(String[] args) throws Exception {
	int port = 8080;
	if (args != null && args.length > 0) {
	    try {
		port = Integer.valueOf(args[0]);
	    } catch (NumberFormatException e) {
		// 采用默认值
	    }
	}
	new TimeServer().bind(port);
    }
}

/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package com.phei.netty.basic;

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

/**
 * @author lilinfeng
 * @date 2014年2月14日
 * @version 1.0
 */
public class TimeServerHandler extends ChannelHandlerAdapter {

    @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("The time server receive order : " + body);
	String currentTime = "QUERY TIME ORDER".equalsIgnoreCase(body) ? new java.util.Date(
		System.currentTimeMillis()).toString() : "BAD ORDER";
	ByteBuf resp = Unpooled.copiedBuffer(currentTime.getBytes());
	ctx.write(resp);
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
	ctx.flush();
    }

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

/*
 * Copyright 2013-2018 Lilinfeng.
 *  
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.phei.netty.basic;

import io.netty.bootstrap.Bootstrap;
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.NioSocketChannel;

/**
 * @author lilinfeng
 * @date 2014年2月14日
 * @version 1.0
 */
public class TimeClient {

    public void connect(int port, String host) throws Exception {
	// 配置客户端NIO线程组
	EventLoopGroup group = new NioEventLoopGroup();
	try {
	    Bootstrap b = new Bootstrap();
	    b.group(group).channel(NioSocketChannel.class)
		    .option(ChannelOption.TCP_NODELAY, true)
		    .handler(new ChannelInitializer<SocketChannel>() {
			@Override
			public void initChannel(SocketChannel ch)
				throws Exception {
			    ch.pipeline().addLast(new TimeClientHandler());
			}
		    });

	    // 发起异步连接操作
	    ChannelFuture f = b.connect(host, port).sync();

	    // 当代客户端链路关闭
	    f.channel().closeFuture().sync();
	} finally {
	    // 优雅退出，释放NIO线程组
	    group.shutdownGracefully();
	}
    }

    /**
     * @param args
     * @throws Exception
     */
    public static void main(String[] args) throws Exception {
	int port = 8080;
	if (args != null && args.length > 0) {
	    try {
		port = Integer.valueOf(args[0]);
	    } catch (NumberFormatException e) {
		// 采用默认值
	    }
	}
	new TimeClient().connect(port, "127.0.0.1");
    }
}

/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package com.phei.netty.basic;

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

import java.util.logging.Logger;

/**
 * @author lilinfeng
 * @date 2014年2月14日
 * @version 1.0
 */
public class TimeClientHandler extends ChannelHandlerAdapter {

    private static final Logger logger = Logger
	    .getLogger(TimeClientHandler.class.getName());

    private final ByteBuf firstMessage;

    /**
     * Creates a client-side handler.
     */
    public TimeClientHandler() {
	byte[] req = "QUERY TIME ORDER".getBytes();
	firstMessage = Unpooled.buffer(req.length);
	firstMessage.writeBytes(req);

    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) {
	ctx.writeAndFlush(firstMessage);
    }

    @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("Now is : " + body);
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
	// 释放资源
	logger.warning("Unexpected exception from downstream : "
		+ cause.getMessage());
	ctx.close();
    }
}