Netty处理HTTP之GET,POST请求

这里使用浏览器发出http请求，也可以使用netty写http的客户端。从浏览器请求http://localhost:8080/，服务器会生成两个form表单，一个form表单是get请求，一个是post请求，经过netty的request解码器，封装成HttpObject对象，判断对象是否是HttpRequest对象，是的话执行代码。

注：浏览器发出的/favicon.ico请求

浏览器调用favicon的原理是首先在网页所在目录寻找favicon.ico文件，如果没有找到就去网站的根目录寻找。所以最简单的方法就是将制作好的favicon文件命名为favicon.ico然后上传到网站的根目录下。

Netty的http对象都是Netty自己封装的，不是标准的。

先看http的服务器端。服务器的代码一般就是这样。

package http.lyx3;    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;    /**   * A HTTP server showing how to use the HTTP multipart package for file uploads.   */  public class HttpDemoServer {        private final int port;      public static boolean isSSL;        public HttpDemoServer(int port) {          this.port = port;      }        public void run() throws Exception {          EventLoopGroup bossGroup = new NioEventLoopGroup(1);          EventLoopGroup workerGroup = new NioEventLoopGroup();          try {              ServerBootstrap b = new ServerBootstrap();              b.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class)                      .childHandler(new HttpDemoServerInitializer());                Channel ch = b.bind(port).sync().channel();              System.out.println("HTTP Upload Server at port " + port + '.');              System.out.println("Open your browser and navigate to http://localhost:" + port + '/');                ch.closeFuture().sync();          } finally {              bossGroup.shutdownGracefully();              workerGroup.shutdownGracefully();          }      }        public static void main(String[] args) throws Exception {          int port;          if (args.length > 0) {              port = Integer.parseInt(args[0]);          } else {              port = 8080;          }          if (args.length > 1) {              isSSL = true;          }          new HttpDemoServer(port).run();      }  }

初始化服务器端handler的代码

package http.lyx3;    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.HttpRequestDecoder;  import io.netty.handler.codec.http.HttpResponseEncoder;  import io.netty.handler.ssl.SslHandler;  import securechat.SecureChatSslContextFactory;    import javax.net.ssl.SSLEngine;    public class HttpDemoServerInitializer extends ChannelInitializer<SocketChannel> {      @Override      public void initChannel(SocketChannel ch) throws Exception {          // Create a default pipeline implementation.          ChannelPipeline pipeline = ch.pipeline();            if (HttpDemoServer.isSSL) {              SSLEngine engine = SecureChatSslContextFactory.getServerContext().createSSLEngine();              engine.setUseClientMode(false);              pipeline.addLast("ssl", new SslHandler(engine));          }            /**           * http-request解码器           * http服务器端对request解码           */          pipeline.addLast("decoder", new HttpRequestDecoder());          /**           * http-response解码器           * http服务器端对response编码           */          pipeline.addLast("encoder", new HttpResponseEncoder());            /**           * 压缩           * Compresses an HttpMessage and an HttpContent in gzip or deflate encoding           * while respecting the "Accept-Encoding" header.           * If there is no matching encoding, no compression is done.           */          pipeline.addLast("deflater", new HttpContentCompressor());            pipeline.addLast("handler", new HttpDemoServerHandler());      }  }

最重要的是handler，处理http请求，返回http响应（返回响应给浏览器）

package http.lyx3;    import io.netty.buffer.ByteBuf;  import io.netty.channel.*;  import io.netty.handler.codec.http.*;  import io.netty.handler.codec.http.multipart.*;  import io.netty.handler.codec.http.multipart.HttpPostRequestDecoder.EndOfDataDecoderException;  import io.netty.handler.codec.http.multipart.HttpPostRequestDecoder.ErrorDataDecoderException;  import io.netty.handler.codec.http.multipart.InterfaceHttpData.HttpDataType;  import io.netty.util.CharsetUtil;    import java.io.IOException;  import java.net.URI;  import java.util.Collections;  import java.util.List;  import java.util.Map;  import java.util.Map.Entry;  import java.util.Set;    import static io.netty.buffer.Unpooled.copiedBuffer;  import static io.netty.handler.codec.http.HttpHeaders.Names.*;    public class HttpDemoServerHandler extends SimpleChannelInboundHandler<HttpObject> {        private HttpRequest request;        private boolean readingChunks;        private final StringBuilder responseContent = new StringBuilder();        private static final HttpDataFactory factory = new DefaultHttpDataFactory(DefaultHttpDataFactory.MINSIZE); //Disk        private HttpPostRequestDecoder decoder;        @Override      public void channelInactive(ChannelHandlerContext ctx) throws Exception {          if (decoder != null) {              decoder.cleanFiles();          }      }        public void messageReceived(ChannelHandlerContext ctx, HttpObject msg) throws Exception {            System.err.println(msg.getClass().getName());          /**           * msg的类型           * {@link DefaultHttpRequest}           * {@link LastHttpContent}           */          if (msg instanceof HttpRequest) {              HttpRequest request = this.request = (HttpRequest) msg;              URI uri = new URI(request.getUri());              System.err.println("request uri==" + uri.getPath());                if (uri.getPath().equals("/favicon.ico")) {                  return;              }              if (uri.getPath().equals("/")) {                  writeMenu(ctx);                  return;              }              responseContent.setLength(0);              responseContent.append("WELCOME TO THE WILD WILD WEB SERVER\r\n");              responseContent.append("===================================\r\n");                responseContent.append("VERSION: " + request.getProtocolVersion().text() + "\r\n");                responseContent.append("REQUEST_URI: " + request.getUri() + "\r\n\r\n");              responseContent.append("\r\n\r\n");                // new getMethod              for (Entry<String, String> entry : request.headers()) {                  responseContent.append("HEADER: " + entry.getKey() + '=' + entry.getValue() + "\r\n");              }              responseContent.append("\r\n\r\n");                // new getMethod              Set<Cookie> cookies;              String value = request.headers().get(COOKIE);              if (value == null) {                  /**                   * Returns an empty set (immutable).                   */                  cookies = Collections.emptySet();              } else {                  cookies = CookieDecoder.decode(value);              }              for (Cookie cookie : cookies) {                  responseContent.append("COOKIE: " + cookie.toString() + "\r\n");              }              responseContent.append("\r\n\r\n");                /**               * List<String>表示当参数相同时，把相同的参数的值放在list中               */              QueryStringDecoder decoderQuery = new QueryStringDecoder(request.getUri());              Map<String, List<String>> uriAttributes = decoderQuery.parameters();              for (Entry<String, List<String>> attr : uriAttributes.entrySet()) {                  for (String attrVal : attr.getValue()) {                      responseContent.append("URI: " + attr.getKey() + '=' + attrVal + "\r\n");                  }              }              responseContent.append("\r\n\r\n");                // if GET Method: should not try to create a HttpPostRequestDecoder              if (request.getMethod().equals(HttpMethod.GET)) {                  // GET Method: should not try to create a HttpPostRequestDecoder                  // So stop here                  responseContent.append("\r\n\r\nEND OF GET CONTENT\r\n");                  writeResponse(ctx.channel());                  return;              }                  //判断request请求是否是post请求              if (request.getMethod().equals(HttpMethod.POST)) {                  System.err.println("===this is http post===");                  try {                      /**                       * 通过HttpDataFactory和request构造解码器                       */                      decoder = new HttpPostRequestDecoder(factory, request);                  } catch (ErrorDataDecoderException e1) {                      e1.printStackTrace();                      responseContent.append(e1.getMessage());                      writeResponse(ctx.channel());                      ctx.channel().close();                      return;                  }                    readingChunks = HttpHeaders.isTransferEncodingChunked(request);                  responseContent.append("Is Chunked: " + readingChunks + "\r\n");                  responseContent.append("IsMultipart: " + decoder.isMultipart() + "\r\n");                  if (readingChunks) {                      // Chunk version                      responseContent.append("Chunks: ");                      readingChunks = true;                  }              }          }            if (decoder != null) {              if (msg instanceof HttpContent) {                  // New chunk is received                  HttpContent chunk = (HttpContent) msg;                  try {                      decoder.offer(chunk);                  } catch (ErrorDataDecoderException e1) {                      e1.printStackTrace();                      responseContent.append(e1.getMessage());                      writeResponse(ctx.channel());                      ctx.channel().close();                      return;                  }                  responseContent.append('o');                  try {                      while (decoder.hasNext()) {                          InterfaceHttpData data = decoder.next();                          if (data != null) {                              try {                                  writeHttpData(data);                              } finally {                                  data.release();                              }                          }                      }                  } catch (EndOfDataDecoderException e1) {                      responseContent.append("\r\n\r\nEND OF CONTENT CHUNK BY CHUNK\r\n\r\n");                  }                    // example of reading only if at the end                  if (chunk instanceof LastHttpContent) {                      writeResponse(ctx.channel());                      readingChunks = false;                      reset();                  }              }          }      }        private void reset() {          request = null;          // destroy the decoder to release all resources          decoder.destroy();          decoder = null;      }        private void writeHttpData(InterfaceHttpData data) {          /**           * HttpDataType有三种类型           * Attribute, FileUpload, InternalAttribute           */          if (data.getHttpDataType() == HttpDataType.Attribute) {              Attribute attribute = (Attribute) data;              String value;              try {                  value = attribute.getValue();              } catch (IOException e1) {                  e1.printStackTrace();                  responseContent.append("\r\nBODY Attribute: " + attribute.getHttpDataType().name() + ":"                          + attribute.getName() + " Error while reading value: " + e1.getMessage() + "\r\n");                  return;              }              if (value.length() > 100) {                  responseContent.append("\r\nBODY Attribute: " + attribute.getHttpDataType().name() + ":"                          + attribute.getName() + " data too long\r\n");              } else {                  responseContent.append("\r\nBODY Attribute: " + attribute.getHttpDataType().name() + ":"                          + attribute.toString() + "\r\n");              }          }      }        private void writeResponse(Channel channel) {          // Convert the response content to a ChannelBuffer.          ByteBuf buf = copiedBuffer(responseContent.toString(), CharsetUtil.UTF_8);          responseContent.setLength(0);            // Decide whether to close the connection or not.          boolean close = request.headers().contains(CONNECTION, HttpHeaders.Values.CLOSE, true)                  || request.getProtocolVersion().equals(HttpVersion.HTTP_1_0)                  && !request.headers().contains(CONNECTION, HttpHeaders.Values.KEEP_ALIVE, true);            // Build the response object.          FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK, buf);          response.headers().set(CONTENT_TYPE, "text/plain; charset=UTF-8");            if (!close) {              // There's no need to add 'Content-Length' header              // if this is the last response.              response.headers().set(CONTENT_LENGTH, buf.readableBytes());          }            Set<Cookie> cookies;          String value = request.headers().get(COOKIE);          if (value == null) {              cookies = Collections.emptySet();          } else {              cookies = CookieDecoder.decode(value);          }          if (!cookies.isEmpty()) {              // Reset the cookies if necessary.              for (Cookie cookie : cookies) {                  response.headers().add(SET_COOKIE, ServerCookieEncoder.encode(cookie));              }          }          // Write the response.          ChannelFuture future = channel.writeAndFlush(response);          // Close the connection after the write operation is done if necessary.          if (close) {              future.addListener(ChannelFutureListener.CLOSE);          }      }        private void writeMenu(ChannelHandlerContext ctx) {          // print several HTML forms          // Convert the response content to a ChannelBuffer.          responseContent.setLength(0);            // create Pseudo Menu          responseContent.append("<html>");          responseContent.append("<head>");          responseContent.append("<title>Netty Test Form</title>\r\n");          responseContent.append("</head>\r\n");          responseContent.append("<body bgcolor=white><style>td{font-size: 12pt;}</style>");            responseContent.append("<table border=\"0\">");          responseContent.append("<tr>");          responseContent.append("<td>");          responseContent.append("<h1>Netty Test Form</h1>");          responseContent.append("Choose one FORM");          responseContent.append("</td>");          responseContent.append("</tr>");          responseContent.append("</table>\r\n");            // GET          responseContent.append("<CENTER>GET FORM<HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");          responseContent.append("<FORM ACTION=\"/from-get\" METHOD=\"GET\">");          responseContent.append("<input type=hidden name=getform value=\"GET\">");          responseContent.append("<table border=\"0\">");          responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"info\" size=10></td></tr>");          responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"info\" size=10></td></tr>");          responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"secondinfo\" size=20>");          responseContent                  .append("<tr><td>Fill with value: <br> <textarea name=\"thirdinfo\" cols=40 rows=10></textarea>");          responseContent.append("</td></tr>");          responseContent.append("<tr><td><INPUT TYPE=\"submit\" NAME=\"Send\" VALUE=\"Send\"></INPUT></td>");          responseContent.append("<td><INPUT TYPE=\"reset\" NAME=\"Clear\" VALUE=\"Clear\" ></INPUT></td></tr>");          responseContent.append("</table></FORM>\r\n");          responseContent.append("<CENTER><HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");            // POST          responseContent.append("<CENTER>POST FORM<HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");          responseContent.append("<FORM ACTION=\"/from-post\" METHOD=\"POST\">");          responseContent.append("<input type=hidden name=getform value=\"POST\">");          responseContent.append("<table border=\"0\">");          responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"info\" size=10></td></tr>");          responseContent.append("<tr><td>Fill with value: <br> <input type=text name=\"secondinfo\" size=20>");          responseContent                  .append("<tr><td>Fill with value: <br> <textarea name=\"thirdinfo\" cols=40 rows=10></textarea>");          responseContent.append("<tr><td>Fill with file (only file name will be transmitted): <br> "                  + "<input type=file name=\"myfile\">");          responseContent.append("</td></tr>");          responseContent.append("<tr><td><INPUT TYPE=\"submit\" NAME=\"Send\" VALUE=\"Send\"></INPUT></td>");          responseContent.append("<td><INPUT TYPE=\"reset\" NAME=\"Clear\" VALUE=\"Clear\" ></INPUT></td></tr>");          responseContent.append("</table></FORM>\r\n");          responseContent.append("<CENTER><HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");          responseContent.append("<CENTER><HR WIDTH=\"75%\" NOSHADE color=\"blue\"></CENTER>");          responseContent.append("</body>");          responseContent.append("</html>");            ByteBuf buf = copiedBuffer(responseContent.toString(), CharsetUtil.UTF_8);          // Build the response object.          FullHttpResponse response = new DefaultFullHttpResponse(                  HttpVersion.HTTP_1_1, HttpResponseStatus.OK, buf);            response.headers().set(CONTENT_TYPE, "text/html; charset=UTF-8");          response.headers().set(CONTENT_LENGTH, buf.readableBytes());            // Write the response.          ctx.channel().writeAndFlush(response);      }        @Override      public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {          ctx.channel().close();      }        @Override      protected void channelRead0(ChannelHandlerContext ctx, HttpObject msg) throws Exception {          messageReceived(ctx, msg);      }  }