Netty(一)：netty的入门使用。

Netty的入门基本使用流程代码,不做具体分析。使用版本为Netty 4.x版本。

服务端调用示例：

　　绑定端口号为8080端口

package com.cllover;

import com.sun.webkit.EventLoop;
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 Server {
    public static void main(String[] args) {

        //接受连接
        EventLoopGroup parentEventLoopGroup = new NioEventLoopGroup();
        EventLoopGroup childEventLoopGroup = new NioEventLoopGroup();

        try {
            //入口
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(parentEventLoopGroup,childEventLoopGroup).
                channel(NioServerSocketChannel.class).childHandler(new Init());
        //绑定运行端口
            ChannelFuture channelFuture = serverBootstrap.bind(8080).sync();
            channelFuture.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally {
            //连接关闭
            parentEventLoopGroup.shutdownGracefully();
            childEventLoopGroup.shutdownGracefully();
        }


    }
}

 Init：初始化类

package com.cllover;

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 Init extends ChannelInitializer<SocketChannel> {

    @Override
    protected void initChannel(SocketChannel ch) throws Exception {
        ChannelPipeline pipeline = ch.pipeline();
        pipeline.addLast("httpServerCode",new HttpServerCodec());
        pipeline.addLast("httpServerHandler",new HttpServerHandler());

    }
}

HttpServerHandler：自定义服务端处理器

package com.cllover;

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 HttpServerHandler extends SimpleChannelInboundHandler<HttpObject> {

    /*
    * 数据处理方法
    * */
    @Override
    protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Exception {

        if (msg instanceof HttpRequest) {
            ByteBuf byteBuf = Unpooled.copiedBuffer("Hello World!", CharsetUtil.UTF_8);
            FullHttpResponse fullHttpResponse = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1,
                    HttpResponseStatus.OK, byteBuf);

　　　　　　　　//加入头信息
            fullHttpResponse.headers().set(HttpHeaderNames.ACCEPT_CHARSET, "UTF_8");
            fullHttpResponse.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/plain");
            fullHttpResponse.headers().set(HttpHeaderNames.CONTENT_LENGTH, byteBuf.readableBytes());
            ctx.writeAndFlush(fullHttpResponse);
        }
    }
}

运行方式：

1. 在本机windows/子系统linux上输入:curl locaclhost:8080

　　2.在浏览器输入localhost：8080

头信息：