Netty server demo

小鱼儿 2022-07-15 16:13 185阅读 0赞

## Netty server demo ##

#### 一、简介 ####

> Netty是一个高性能、异步事件驱动的NIO框架，它提供了对TCP、UDP和文件传输的支持，作为一个异步NIO框架，Netty的所有IO操作都是异步非阻塞的，通过Future-Listener机制，用户可以方便的主动获取或者通过通知机制获得IO操作结果

#### 二、maven依赖 ####

<dependency>
        <groupId>io.netty</groupId>
        <artifactId>netty-transport</artifactId>
        <version>4.1.6.Final</version>
    </dependency>
    
    
    <dependency>
        <groupId>io.netty</groupId>
        <artifactId>netty-handler</artifactId>
        <version>4.1.6.Final</version>
    </dependency>

#### 三、示列代码 ####

package netty;
    
    import io.netty.bootstrap.ServerBootstrap;
    import io.netty.channel.ChannelFuture;
    import io.netty.channel.ChannelInitializer;
    import io.netty.channel.ChannelPipeline;
    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 io.netty.handler.logging.LogLevel;
    import io.netty.handler.logging.LoggingHandler;
    
    import java.util.concurrent.ExecutionException;
    
    
    /** * Created by zhengyong on 16/10/21. */
    public class NettyServer {
    
        private static ServerBootstrap bootstrap;
    
        public static void main(String[] args) throws InterruptedException, ExecutionException {
    
            EventLoopGroup boss = new NioEventLoopGroup(1);
            EventLoopGroup worker = new NioEventLoopGroup();
    
            bootstrap = new ServerBootstrap();
            bootstrap.group(boss,worker).channel(NioServerSocketChannel.class).handler(new LoggingHandler(LogLevel.INFO))
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                @Override
                public void initChannel(SocketChannel ch) throws Exception {
                    ChannelPipeline p = ch.pipeline();
                    p.addLast(new ConsoleHandler());
                }
            });
    
            // Start the client.
            ChannelFuture ch = bootstrap.bind(8082).sync();
    
            System.out.println("start server success, you can telnet 127.0.0.1 8082 to send massage for this server");
    
            // Wait until the connection is closed.
            ch.channel().closeFuture().sync();
    
        }
    }

package netty;
    
    import io.netty.channel.ChannelHandlerContext;
    import io.netty.channel.ChannelInboundHandlerAdapter;
    
    import java.io.UnsupportedEncodingException;
    
    /** * Created by zhengyong on 16/10/21. */
    public class ConsoleHandler extends ChannelInboundHandlerAdapter { 
    
        @Override
        public void channelRead(ChannelHandlerContext ctx, Object msg) throws UnsupportedEncodingException {
    
            System.out.println(msg);
            ctx.write(msg);
        }
    
        @Override
        public void channelReadComplete(ChannelHandlerContext ctx) {
            ctx.flush();
        }
    }

#### 四、运行结果 ####

telnet 控制台

![telnet image][]

idea控制台

start server success, you can telnet 127.0.0.1 8082 to send massage for this server
    PooledUnsafeDirectByteBuf(ridx: 0, widx: 7, cap: 1024)
    PooledUnsafeDirectByteBuf(ridx: 0, widx: 7, cap: 1024)

##### 五、参考 #####

1.  [http://www.infoq.com/cn/articles/netty-high-performance][http_www.infoq.com_cn_articles_netty-high-performance]
2.  [https://my.oschina.net/plucury/blog/192577][https_my.oschina.net_plucury_blog_192577]

[telnet image]: /images/20220715/b0b7a8520c104871b5558f5da5da6090.png
[http_www.infoq.com_cn_articles_netty-high-performance]: http://www.infoq.com/cn/articles/netty-high-performance
[https_my.oschina.net_plucury_blog_192577]: https://my.oschina.net/plucury/blog/192577