netty整合springMVC，实现高效的HTTP服务请求

参考http://blog.csdn.net/imlsz/article/details/42673507的代码，谢谢！不过在处理返回servlet的结果时候，按照上文的方法不行。

首先，你必须要了解netty，说简单点：客户端通过TCP链接和服务器建立长连接，client和server都是通过管道（ChannelPipeline）的addLast方法的添加顺序来处理接收或者发送的数据。这个和struts的filter的doFilter原理类似，处理完一个filter，如果后面还有其他的filter，就将数据chain.doFilter来继续处理。

然后，说说netty怎么来整合springMVC：当client和server建立连接后，我们在addLast的某个类中将client发来的请求，让DispatcherServlet来处理，然后将处理后的结果通过ChannelHandlerContext或者Channel将,结果writeAndFlush到client。

1.写一个netty sever的java代码

package com.magic.netty.server;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.web.servlet.DispatcherServlet;import io.netty.bootstrap.ServerBootstrap;import io.netty.channel.ChannelFuture;import io.netty.channel.ChannelOption;import io.netty.channel.EventLoopGroup;import io.netty.channel.nio.NioEventLoopGroup;import io.netty.channel.socket.nio.NioServerSocketChannel;import com.magic.netty.HttpServerInitializer;public class NettyHttpServer {    public NettyHttpServer(Integer port) {        this.port = port;    }    public NettyHttpServer(Integer port, DispatcherServlet servlet) {        this.port = port;        this.servlet = servlet;    }    public void start(){        EventLoopGroup bossGroup = new NioEventLoopGroup();        EventLoopGroup workerGroup = new NioEventLoopGroup();        try {            ServerBootstrap b = new ServerBootstrap();            b.group(bossGroup, workerGroup)                    .channel(NioServerSocketChannel.class)                    .childHandler(new HttpServerInitializer(servlet))                    .option(ChannelOption.SO_BACKLOG, 128)                    .childOption(ChannelOption.SO_KEEPALIVE, true);            System.out.println("NettyHttpServer Run successfully");            // 绑定端口，开始接收进来的连接            ChannelFuture f = b.bind(port).sync();            // 等待服务器 socket 关闭 。在这个例子中，这不会发生，但你可以优雅地关闭你的服务器。            f.channel().closeFuture().sync();        } catch (Exception e) {            log.error("NettySever start fail",e);        } finally {            workerGroup.shutdownGracefully();            bossGroup.shutdownGracefully();        }    }    private int port;    private static Logger log = LoggerFactory.getLogger(NettyHttpServer.class);    private DispatcherServlet servlet;}

2.初始化netty的channel管道

package com.magic.netty;import org.springframework.web.servlet.DispatcherServlet;import io.netty.channel.ChannelInitializer;import io.netty.channel.ChannelPipeline;import io.netty.channel.socket.SocketChannel;import io.netty.handler.codec.http.HttpContentCompressor;import io.netty.handler.codec.http.HttpObjectAggregator;import io.netty.handler.codec.http.HttpRequestDecoder;import io.netty.handler.codec.http.HttpResponseEncoder;import io.netty.handler.stream.ChunkedWriteHandler;public class HttpServerInitializer extends ChannelInitializer<SocketChannel> {    public HttpServerInitializer(DispatcherServlet servlet) {        this.servlet = servlet;    }    public HttpServerInitializer() {    }    @Override    protected void initChannel(SocketChannel ch) throws Exception {        ChannelPipeline pipeline = ch.pipeline();        pipeline.addLast("decoder", new HttpRequestDecoder());        pipeline.addLast("encoder", new HttpResponseEncoder());        pipeline.addLast("aggregator", new HttpObjectAggregator(2147483647));        pipeline.addLast("chunkedWriter", new ChunkedWriteHandler());        pipeline.addLast("deflater", new HttpContentCompressor());        pipeline.addLast("handler", new HttpRequestHandler(servlet));    }    private DispatcherServlet servlet;}

3.在handler里面处理client发来的请求

package com.magic.netty;import java.io.UnsupportedEncodingException;import java.net.URLDecoder;import java.util.HashMap;import java.util.Iterator;import java.util.List;import java.util.Map;import java.util.Map.Entry;import javax.servlet.ServletContext;import io.netty.buffer.ByteBuf;import io.netty.buffer.Unpooled;import io.netty.channel.ChannelFuture;import io.netty.channel.ChannelFutureListener;import io.netty.channel.ChannelHandlerContext;import io.netty.channel.SimpleChannelInboundHandler;import io.netty.handler.codec.http.*;import io.netty.handler.codec.http.multipart.DefaultHttpDataFactory;import io.netty.handler.codec.http.multipart.HttpPostRequestDecoder;import io.netty.handler.codec.http.multipart.InterfaceHttpData;import io.netty.handler.codec.http.multipart.InterfaceHttpData.HttpDataType;import io.netty.handler.codec.http.multipart.MemoryAttribute;import io.netty.util.CharsetUtil;import org.apache.commons.lang3.StringUtils;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.mock.web.MockHttpServletRequest;import org.springframework.mock.web.MockHttpServletResponse;import org.springframework.web.servlet.DispatcherServlet;import org.springframework.web.util.UriComponents;import org.springframework.web.util.UriComponentsBuilder;import org.springframework.web.util.UriUtils;public class HttpRequestHandler extends SimpleChannelInboundHandler<FullHttpRequest> {    public HttpRequestHandler(DispatcherServlet servlet) {        this.servlet = servlet;        this.servletContext = servlet.getServletConfig().getServletContext();    }    @Override    public void exceptionCaught(ChannelHandlerContext ctx, Throwable e) throws Exception {        logger.error(e.getMessage(),e);        ctx.close();    }    protected void channelRead0(ChannelHandlerContext ctx, FullHttpRequest fullHttpRequest) throws Exception {        boolean flag = HttpMethod.POST.equals(fullHttpRequest.getMethod())                || HttpMethod.GET.equals(fullHttpRequest.getMethod());        Map<String, String>  parammap = getRequestParams(ctx,fullHttpRequest);        if(flag && ctx.channel().isActive()){            //HTTP请求、GET/POST            MockHttpServletResponse servletResponse = new MockHttpServletResponse();            MockHttpServletRequest servletRequest =new MockHttpServletRequest(servletContext);            // headers            for (String name : fullHttpRequest.headers().names()) {                for (String value : fullHttpRequest.headers().getAll(name)) {                    servletRequest.addHeader(name, value);                }            }            String uri = fullHttpRequest.getUri();            uri = new String(uri.getBytes("ISO8859-1"), "UTF-8");            uri = URLDecoder.decode(uri, "UTF-8");            UriComponents uriComponents = UriComponentsBuilder.fromUriString(uri).build();            String path = uriComponents.getPath();            path = URLDecoder.decode(path, "UTF-8");            servletRequest.setRequestURI(path);            servletRequest.setServletPath(path);            servletRequest.setMethod(fullHttpRequest.getMethod().name());            if (uriComponents.getScheme() != null) {                servletRequest.setScheme(uriComponents.getScheme());            }            if (uriComponents.getHost() != null) {                servletRequest.setServerName(uriComponents.getHost());            }            if (uriComponents.getPort() != -1) {                servletRequest.setServerPort(uriComponents.getPort());            }            ByteBuf content = fullHttpRequest.content();            content.readerIndex(0);            byte[] data = new byte[content.readableBytes()];            content.readBytes(data);            servletRequest.setContent(data);            try {                if (uriComponents.getQuery() != null) {                    String query = UriUtils.decode(uriComponents.getQuery(),"UTF-8");                    servletRequest.setQueryString(query);                }                if(parammap!=null&&parammap.size()>0){                    for (String key : parammap.keySet()) {                        servletRequest.addParameter(UriUtils.decode(key,"UTF-8"), UriUtils.decode(parammap.get(key) == null ? "": parammap.get(key), "UTF-8"));                    }                }            } catch (UnsupportedEncodingException ex) {                ex.printStackTrace();            }            this.servlet.service(servletRequest,servletResponse);            HttpResponseStatus status = HttpResponseStatus.valueOf(servletResponse.getStatus());            String result = servletResponse.getContentAsString();            result = StringUtils.isEmpty(result)?"":result;            FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, status,Unpooled.copiedBuffer(result,CharsetUtil.UTF_8));            response.headers().set("Content-Type", "text/json;charset=UTF-8");            response.headers().set("Access-Control-Allow-Origin", "*");            response.headers().set("Access-Control-Allow-Headers", "Content-Type,Content-Length, Authorization, Accept,X-Requested-With,X-File-Name");            response.headers().set("Access-Control-Allow-Methods", "PUT,POST,GET,DELETE,OPTIONS");            response.headers().set("Content-Length", Integer.valueOf(response.content().readableBytes()));            response.headers().set("Connection", "keep-alive");            ChannelFuture writeFuture = ctx.writeAndFlush(response);            writeFuture.addListener(ChannelFutureListener.CLOSE);        }    }     /**     * 获取post请求、get请求的参数保存到map中     */    private Map<String, String> getRequestParams(ChannelHandlerContext ctx, HttpRequest req){        Map<String, String>requestParams=new HashMap<String, String>();        // 处理get请求          if (req.getMethod() == HttpMethod.GET) {            QueryStringDecoder decoder = new QueryStringDecoder(req.getUri());              Map<String, List<String>> parame = decoder.parameters();              Iterator<Entry<String, List<String>>> iterator = parame.entrySet().iterator();            while(iterator.hasNext()){                Entry<String, List<String>> next = iterator.next();                requestParams.put(next.getKey(), next.getValue().get(0));            }        }         // 处理POST请求          if (req.getMethod() == HttpMethod.POST) {            HttpPostRequestDecoder decoder = new HttpPostRequestDecoder(                      new DefaultHttpDataFactory(false), req);              List<InterfaceHttpData> postData = decoder.getBodyHttpDatas(); //            for(InterfaceHttpData data:postData){                if (data.getHttpDataType() == HttpDataType.Attribute) {                      MemoryAttribute attribute = (MemoryAttribute) data;                      requestParams.put(attribute.getName(), attribute.getValue());                }            }        }        return requestParams;    }    private static final Logger logger = LoggerFactory.getLogger(HttpRequestHandler.class);    private final DispatcherServlet servlet;    private final ServletContext servletContext;}

4.初始化servlet并启动netty server

package com.magic;import javax.servlet.ServletException;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import org.springframework.mock.web.MockServletConfig;import org.springframework.web.context.support.XmlWebApplicationContext;import org.springframework.web.servlet.DispatcherServlet;import com.magic.common.config.PropConfig;import com.magic.netty.server.NettyHttpServer;public class MagicWebServer {    private static Logger logger = LoggerFactory.getLogger(MagicWebServer.class);    public static void main(String[] args) {        ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");        Integer port = 6001;        DispatcherServlet servlet = getDispatcherServlet(ctx);        NettyHttpServer server = new NettyHttpServer(port,servlet);        server.start();    }    public static DispatcherServlet getDispatcherServlet(ApplicationContext ctx){        XmlWebApplicationContext mvcContext = new XmlWebApplicationContext();        mvcContext.setConfigLocation("classpath:spring-servlet.xml");        mvcContext.setParent(ctx);        MockServletConfig servletConfig = new MockServletConfig(mvcContext.getServletContext(), "dispatcherServlet");        DispatcherServlet dispatcherServlet = new DispatcherServlet(mvcContext);        try {            dispatcherServlet.init(servletConfig);        } catch (ServletException e) {            e.printStackTrace();        }        return dispatcherServlet;    }}

5.写一个controller，并测试一波http://127.0.0.1:6001/user/login

package com.magic.controller;import java.util.HashMap;import java.util.Map;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.ResponseBody;import com.alibaba.fastjson.JSONObject;@Controller@RequestMapping(value="/user",produces = "text/json;charset=utf-8")public class UserController extends BaseController{    @RequestMapping("/login")    @ResponseBody    public String login(String username,String pwd){        JSONObject resultJson = new JSONObject();        Map<String, String> loginResult = new HashMap<String, String>();        loginResult.put("username", username);        loginResult.put("age", "20");        loginResult.put("sex", "boy");        resultJson.put("code", 200);        resultJson.put("msg", "登录成功");        resultJson.put("result", loginResult);        return JSONObject.toJSONString(resultJson);    }}

Mark一下，说明在coding的时候遇到的问题

1. 代码中的applicationContext.xml和spring-servlet.xml的按照springMVC的正常配置就行
2. 如果返回到client端的代码有中午乱码，那么在requestMapping里面添加produces = “text/json;charset=utf-8”。