Netty4服务端入门代码示例

添加Maven依赖

        <dependency>
            <groupId>io.netty</groupId>
            <artifactId>netty-all</artifactId>
            <version>4.1.36.Final</version>
        </dependency>

代码示例：

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;

public class NetttyServer
{
    public static void main(String[] args)
    {
        EventLoopGroup boss = new NioEventLoopGroup();
        EventLoopGroup worker = new NioEventLoopGroup();
        ServerBootstrap bootstrap = new ServerBootstrap();
        bootstrap.group(boss,worker)
                .channel(NioServerSocketChannel.class)
                .childHandler(new ChannelInitializer<SocketChannel>()
                {
                    @Override
                    protected void initChannel(SocketChannel socketChannel) throws Exception
                    {
                        socketChannel.pipeline()
                                .addLast("encoder",new StringEncoder())
                                .addLast("decoder",new StringDecoder())
                                .addLast("hello world hanlder",new HelloWorldHandler());

                    }
                });
        try
        {
            ChannelFuture channelFuture = bootstrap.bind(8080).sync();
            channelFuture.channel().closeFuture().sync();
        } catch (InterruptedException e){
            e.printStackTrace();
        }finally
        {
            boss.shutdownGracefully();
            worker.shutdownGracefully();
        }
    }

    static class HelloWorldHandler extends ChannelInboundHandlerAdapter
    {
        @Override
        public void channelActive(ChannelHandlerContext ctx) throws Exception
        {
            System.out.println("channel Active and write back......");
            String resp = "Hello world";
            ChannelFuture future = ctx.channel().writeAndFlush(resp);
            future.sync();

            System.out.println("success:"+future.isSuccess());
            //super.channelActive(ctx);
        }

        public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
            System.out.println("read msg : "+msg);
            String resp = "Hello world";
            ctx.channel().writeAndFlush(resp);
        }
    }
}