1) 实例要求： 使用 IDEA 创建 Netty 项目
2) Netty 服务器在 6668 端口监听， 浏览器发出请求 "http://localhost:6668/ "
3) 服务器可以回复消息给客户端 "Hello! 我是服务器 5 " , 并对特定请求资源进行过滤.
4) 目的： Netty 可以做 Http 服务开发， 并且理解 Handler 实例和客户端及其请求的关系.
TestHttpServerHandler
package com.atguigu.netty.http; 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; import java.net.URI; /* 说明 1. SimpleChannelInboundHandler 是 ChannelInboundHandlerAdapter 2. HttpObject 客户端和服务器端相互通讯的数据被封装成 HttpObject */ public class TestHttpServerHandler extends SimpleChannelInboundHandler<HttpObject> { //channelRead0 读取客户端数据 @Override protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Exception { System.out.println("对应的channel=" + ctx.channel() + " pipeline=" + ctx .pipeline() + " 通过pipeline获取channel" + ctx.pipeline().channel()); System.out.println("当前ctx的handler=" + ctx.handler()); //判断 msg 是不是 httprequest请求 if(msg instanceof HttpRequest) { System.out.println("ctx 类型="+ctx.getClass()); System.out.println("pipeline hashcode" + ctx.pipeline().hashCode() + " TestHttpServerHandler hash=" + this.hashCode()); System.out.println("msg 类型=" + msg.getClass()); System.out.println("客户端地址" + ctx.channel().remoteAddress()); //获取到 HttpRequest httpRequest = (HttpRequest) msg; //获取uri, 过滤指定的资源 URI uri = new URI(httpRequest.uri()); if("/favicon.ico".equals(uri.getPath())) { System.out.println("请求了 favicon.ico, 不做响应"); return; } //回复信息给浏览器 [http协议] ByteBuf content = Unpooled.copiedBuffer("hello, 我是服务器", CharsetUtil.UTF_8); //构造一个http的相应，即 httpresponse FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, content); response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/plain"); response.headers().set(HttpHeaderNames.CONTENT_LENGTH, content.readableBytes()); //将构建好 response返回 ctx.writeAndFlush(response); } } }
TestServer
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(1); EventLoopGroup workerGroup = new NioEventLoopGroup(); try { ServerBootstrap serverBootstrap = new ServerBootstrap(); serverBootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class).childHandler(new TestServerInitializer()); ChannelFuture channelFuture = serverBootstrap.bind(6668).sync(); channelFuture.channel().closeFuture().sync(); }finally { bossGroup.shutdownGracefully(); workerGroup.shutdownGracefully(); } } }
TestServerInitializer
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 TestServerInitializer extends ChannelInitializer<SocketChannel> {
@Override
protected void initChannel(SocketChannel ch) throws Exception {
//向管道加入处理器
//得到管道
ChannelPipeline pipeline = ch.pipeline();
//加入一个netty 提供的httpServerCodec codec =>[coder - decoder]
//HttpServerCodec 说明
//1. HttpServerCodec 是netty 提供的处理http的 编-解码器
pipeline.addLast("MyHttpServerCodec",new HttpServerCodec());
//2. 增加一个自定义的handler
pipeline.addLast("MyTestHttpServerHandler", new TestHttpServerHandler());
System.out.println("ok~~~~");
}
}
原文：https://www.cnblogs.com/cb1186512739/p/12774261.html
