4、hello world

package com.ourteam.firstexample;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;

public class TestServer {

public static void main(String[] args) throws Exception{
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();

try {
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(bossGroup,workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .childHandler(new TestSeriverInitalizer());
            ChannelFuture channelFuture = serverBootstrap.bind(8899).sync();
            channelFuture.channel().closeFuture().sync();
        }finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }

}

package com.ourteam.firstexample;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.http.HttpServerCodec;

public class TestSeriverInitalizer extends ChannelInitializer<SocketChannel> {
    @Override
    protected void initChannel(SocketChannel ch) throws Exception {
        ChannelPipeline pipeline = ch.pipeline();
        pipeline.addLast("httpServerCodec",new HttpServerCodec());
        pipeline.addLast("testHttpServerHandler",new TestHttpServerHandler());
    }
}

package com.ourteam.firstexample;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.*;
import io.netty.util.CharsetUtil;

public class TestHttpServerHandler extends SimpleChannelInboundHandler<HttpObject> {
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Exception {
        if(msg instanceof HttpRequest){
            ByteBuf byteBuf = Unpooled.copiedBuffer("hello world", CharsetUtil.UTF_8);
            DefaultFullHttpResponse respon = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1
                    , HttpResponseStatus.OK, byteBuf);
            respon.headers().set(HttpHeaderNames.CONTENT_TYPE,"text/plain");
            respon.headers().set(HttpHeaderNames.CONTENT_LENGTH,byteBuf.readableBytes());
            ctx.writeAndFlush(respon);
        }
    }
}