Netty处理HTTP之GET,POST请求
jopen
10年前
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); } }