代码参照netty官网例子修改而成，保留最核心的部分

package com.rock.netty.http.t;import java.net.URI;import java.nio.charset.Charset;import io.netty.bootstrap.Bootstrap;import io.netty.channel.Channel;import io.netty.channel.ChannelHandlerContext;import io.netty.channel.ChannelInitializer;import io.netty.channel.ChannelPipeline;import io.netty.channel.EventLoopGroup;import io.netty.channel.SimpleChannelInboundHandler;import io.netty.channel.nio.NioEventLoopGroup;import io.netty.channel.socket.SocketChannel;import io.netty.channel.socket.nio.NioSocketChannel;import io.netty.handler.codec.http.DefaultFullHttpRequest;import io.netty.handler.codec.http.FullHttpRequest;import io.netty.handler.codec.http.FullHttpResponse;import io.netty.handler.codec.http.HttpClientCodec;import io.netty.handler.codec.http.HttpContentDecompressor;import io.netty.handler.codec.http.HttpHeaderNames;import io.netty.handler.codec.http.HttpHeaderValues;import io.netty.handler.codec.http.HttpMethod;import io.netty.handler.codec.http.HttpObjectAggregator;import io.netty.handler.codec.http.HttpVersion;public class NettyHttpClientTest2 {		public static void main(String[] args) throws Exception {		sendRequest("http://www.baidu.com/");	}	private static void sendRequest(String url)throws Exception{		URI uri = new URI(url);		String host = uri.getHost();		int port = 80;		// Configure the client.		EventLoopGroup group = new NioEventLoopGroup();		Bootstrap b = new Bootstrap();		b.group(group).channel(NioSocketChannel.class).handler(new HttpClientInitializer());		// Make the connection attempt.		Channel ch = b.connect(host, port).sync().channel();		// Prepare the HTTP request.		FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET, uri.getRawPath());		request.headers().set(HttpHeaderNames.HOST, host);		request.headers().set(HttpHeaderNames.CONNECTION, HttpHeaderValues.CLOSE);		request.headers().set(HttpHeaderNames.ACCEPT_ENCODING, HttpHeaderValues.GZIP);		// Send the HTTP request.		ch.writeAndFlush(request);		// Wait for the server to close the connection.		ch.closeFuture().sync();		// Shut down executor threads to exit.		group.shutdownGracefully();	}}class HttpClientMsgHandler extends SimpleChannelInboundHandler
    
      {	@Override	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {		cause.printStackTrace();		ctx.close();	}	@Override	protected void channelRead0(ChannelHandlerContext ctx, FullHttpResponse response) throws Exception {		if (!response.headers().isEmpty()) {			for (CharSequence name : response.headers().names()) {				for (CharSequence value : response.headers().getAll(name)) {					System.err.println("HEADER: " + name + " = " + value);				}			}			System.err.println();		}		System.err.println(response.content().toString(Charset.forName("utf-8")));	}}class HttpClientInitializer extends ChannelInitializer
     
       {	@Override	public void initChannel(SocketChannel ch) {		ChannelPipeline p = ch.pipeline();		p.addLast(new HttpClientCodec());		// Remove the following line if you don't want automatic content		// decompression.		p.addLast(new HttpContentDecompressor());//这里要添加解压，不然打印时会乱码		// Uncomment the following line if you don't want to handle		// HttpContents.		// p.addLast(new HttpObjectAggregator(1048576));		p.addLast(new HttpObjectAggregator(123433));//添加HttpObjectAggregator， HttpClientMsgHandler才会收到FullHttpResponse		p.addLast(new HttpClientMsgHandler());	}}