A simple Netty Http server sample. Netty是一套高性能的通讯架构，这里我用netty实现http服务器实现信息采集功能。主要是利用他现有的hander处理器，解析出request头，做信息采集使用，重写了他自己的hander.

new_gist_file_0

package io.netty.example.http.snoop;

import static io.netty.handler.codec.http.HttpHeaders.getHost;
import static io.netty.handler.codec.http.HttpHeaders.isKeepAlive;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_LENGTH;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE;
import static io.netty.handler.codec.http.HttpHeaders.Names.COOKIE;
import static io.netty.handler.codec.http.HttpHeaders.Names.SET_COOKIE;
import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
import static io.netty.handler.codec.http.HttpResponseStatus.OK;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;

import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;

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.Cookie;
import io.netty.handler.codec.http.CookieDecoder;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.HttpContent;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpObject;
import io.netty.handler.codec.http.HttpRequest;
import io.netty.handler.codec.http.LastHttpContent;
import io.netty.handler.codec.http.QueryStringDecoder;
import io.netty.handler.codec.http.ServerCookieEncoder;
import io.netty.util.CharsetUtil;

public class HttpSnoopServiceTxt extends SimpleChannelInboundHandler<Object> {

    private HttpRequest request;
    /** Buffer that stores the response content */
    private final StringBuilder buf = new StringBuilder();

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, Object msg)
            throws Exception {
        // TODO Auto-generated method stub
        if (msg instanceof HttpRequest) {
            HttpRequest request = this.request = (HttpRequest) msg;
            buf.setLength(0);
            // hostname
            buf.append("HOSTNAME:").append(getHost(request, "unknown"));
            // url
            buf.append("REQUEST_URI:").append(request.getUri());
            // parm
            QueryStringDecoder queryStringDecoder = new QueryStringDecoder(request.getUri());
            Map<String, List<String>> params = queryStringDecoder.parameters();
            if (!params.isEmpty()) {
                for (Entry<String, List<String>> p : params.entrySet()) {
                    String key = p.getKey();
                    List<String> vals = p.getValue();
                    for (String val : vals) {
                        buf.append("PARAM:").append(key).append("=")
                                .append(val);
                    }
                }
            }
            //cookie
            
        }
        if (msg instanceof HttpContent) {
            if (msg instanceof LastHttpContent) {
                LastHttpContent trailer = (LastHttpContent) msg;
                writeResponse(trailer, ctx);
                WriterFile.printtxt(buf.toString());
            }
        }
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        ctx.flush();
    }

    private boolean writeResponse(HttpObject currentObj,ChannelHandlerContext ctx) {
        boolean keepAlive = isKeepAlive(request);
        FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1,
                currentObj.getDecoderResult().isSuccess() ? OK : BAD_REQUEST,
                Unpooled.copiedBuffer(buf.toString(), CharsetUtil.UTF_8));
        response.headers().set(CONTENT_TYPE, "text/plain; charset=UTF-8");
        if (keepAlive) {
            response.headers().set(CONTENT_LENGTH,
                    response.content().readableBytes());
            response.headers().set(CONNECTION, HttpHeaders.Values.KEEP_ALIVE);
        }
        ctx.write(response);
        return keepAlive;
    }

}


/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.example.http.snoop;

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

/**
 * An HTTP server that sends back the content of the received HTTP request
 * in a pretty plaintext form.
 */
public class HttpSnoopServer {

    private final int port;

    public HttpSnoopServer(int port) {
        this.port = port;
    }

    public void run() throws Exception {
        // Configure the server.
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup, workerGroup)
             .channel(NioServerSocketChannel.class)
             .childHandler(new HttpSnoopServerInitializer());

            Channel ch = b.bind(port).sync().channel();
            ch.closeFuture().sync();
        } finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }

    public static void main(String[] args) throws Exception {
        int port;
        if (args.length > 0) {
            port = 8080;
        } else {
            port = 8080;
        }
        new HttpSnoopServer(port).run();
    }
}
/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project licenses this file to you under the Apache License,
 * version 2.0 (the "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at:
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */
package io.netty.example.http.snoop;

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

public class HttpSnoopServerInitializer extends ChannelInitializer<SocketChannel> {
    @Override
    public void initChannel(SocketChannel ch) throws Exception {
        // Create a default pipeline implementation.
        ChannelPipeline p = ch.pipeline();

        // Uncomment the following line if you want HTTPS
        //SSLEngine engine = SecureChatSslContextFactory.getServerContext().createSSLEngine();
        //engine.setUseClientMode(false);
        //p.addLast("ssl", new SslHandler(engine));

        p.addLast("decoder", new HttpRequestDecoder());
        // Uncomment the following line if you don't want to handle HttpChunks.
        //p.addLast("aggregator", new HttpObjectAggregator(1048576));
        p.addLast("encoder", new HttpResponseEncoder());
        // Remove the following line if you don't want automatic content compression.
        //p.addLast("deflater", new HttpContentCompressor());
        
        p.addLast("handler", new HttpSnoopServiceTxt());
        //p.addLast("handler", new HttpSnoopServerHandler());
    }
}