使用Netty 4的简单例子详细步骤 _服务器

我觉得这篇文章的标题有点言过其实，因为我无法举出一个对我来说简单的例子。
无论如何，这是一个如何使用Netty使服务器对你进行回应的最小的例子:
NettyExample.java:

import io.netty.bootstrap.ServerBootstrap; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelInboundHandlerAdapter; import io.netty.channel.ChannelInitializer; import io.netty.channel.EventLoopGroup; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.socket.nio.NioServerSocketChannel; import io.netty.channel.socket.SocketChannel; import io.netty.util.CharsetUtil; import io.netty.util.ReferenceCountUtil; import java.nio.charset.Charset; class NettyExample { public static void main( String[] args ) throws Exception { EventLoopGroup bossGroup = new NioEventLoopGroup(); EventLoopGroup workerGroup = new NioEventLoopGroup(); try { new ServerBootstrap() .group( bossGroup, workerGroup ) .channel( NioServerSocketChannel.class ) .childHandler( new Init() ) .bind( 1337 ).sync().channel().closeFuture().sync(); } finally { bossGroup.shutdownGracefully(); workerGroup.shutdownGracefully(); } }private static class Init extends ChannelInitializer { @Override public void initChannel( SocketChannel ch ) throws Exception { ch.pipeline().addLast( new ShoutyHandler() ); } }private static class ShoutyHandler extends ChannelInboundHandlerAdapter { @Override public void channelRead( ChannelHandlerContext ctx, Object msg ) { try { Charset utf8 = CharsetUtil.UTF_8; String in = ( (ByteBuf)msg ).toString( utf8 ); String out = in.toUpperCase(); // Shout! ctx.writeAndFlush( Unpooled.copiedBuffer( out, utf8 ) ); } finally { ReferenceCountUtil.release( msg ); } }@Override public void exceptionCaught( ChannelHandlerContext ctx, Throwable cause ) { cause.printStackTrace(); ctx.close(); } } }

实际执行有用任务的行用红色突出显示。如果有人知道如何缩短它，请在下面评论。对我来说似乎很多。
要运行这个，请做:

sudo apt-get install openjdk-8-jdk wget 'http://search.maven.org/remotecontent?filepath=io/netty/netty-all/4.1.5.Final/netty-all-4.1.5.Final.jar -O netty-all-4.1.5.Final.jar' javac -Werror -cp netty-all-4.1.5.Final.jar:. NettyExample.java & & java -cp netty-all-4.1.5.Final.jar:. NettyExample

然后在另一个终端:

echo "Hello, world" | nc localhost 1337

然后观察响应: HELLO, WORLD
与node . js比较
为了便于比较，在Node.js中有一个近似等价:
【使用Netty 4的简单例子详细步骤】shouty.js:

var net = require('net'); var server = net.createServer( function( socket ) { socket.setEncoding('utf8'); socket.on( 'data', function( data ) { socket.end( data.toUpperCase() ); } ) } ); server.listen( 1337, "localhost" );

执行以下运行程序：