Java tutorial
/* * 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 ch07.handlers; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelFutureListener; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.SimpleChannelInboundHandler; import io.netty.handler.codec.DecoderResult; 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; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import static io.netty.handler.codec.http.HttpHeaders.Names.*; import static io.netty.handler.codec.http.HttpResponseStatus.*; import static io.netty.handler.codec.http.HttpVersion.*; public class HttpSnoopServerHandler extends SimpleChannelInboundHandler<Object> { private HttpRequest request; /** Buffer that stores the response content */ private final StringBuilder buf = new StringBuilder(); @Override public void channelReadComplete(ChannelHandlerContext ctx) { ctx.flush(); } @Override protected void channelRead0(ChannelHandlerContext ctx, Object msg) { if (msg instanceof HttpRequest) { HttpRequest request = this.request = (HttpRequest) msg; if (HttpHeaders.is100ContinueExpected(request)) { send100Continue(ctx); } buf.setLength(0); buf.append("WELCOME TO THE WILD WILD WEB SERVER\r\n"); buf.append("===================================\r\n"); buf.append("VERSION: ").append(request.protocolVersion()).append("\r\n"); buf.append("HOSTNAME: ").append(HttpHeaders.getHost(request, "unknown")).append("\r\n"); buf.append("REQUEST_URI: ").append(request.uri()).append("\r\n\r\n"); HttpHeaders headers = request.headers(); if (!headers.isEmpty()) { for (Map.Entry<String, String> h : headers) { String key = h.getKey(); String value = h.getValue(); buf.append("HEADER: ").append(key).append(" = ").append(value).append("\r\n"); } buf.append("\r\n"); } QueryStringDecoder queryStringDecoder = new QueryStringDecoder(request.uri()); 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).append("\r\n"); } } buf.append("\r\n"); } appendDecoderResult(buf, request); } if (msg instanceof HttpContent) { HttpContent httpContent = (HttpContent) msg; ByteBuf content = httpContent.content(); if (content.isReadable()) { buf.append("CONTENT: "); buf.append(content.toString(CharsetUtil.UTF_8)); buf.append("\r\n"); appendDecoderResult(buf, request); } if (msg instanceof LastHttpContent) { buf.append("END OF CONTENT\r\n"); LastHttpContent trailer = (LastHttpContent) msg; if (!trailer.trailingHeaders().isEmpty()) { buf.append("\r\n"); for (String name : trailer.trailingHeaders().names()) { for (String value : trailer.trailingHeaders().getAll(name)) { buf.append("TRAILING HEADER: "); buf.append(name).append(" = ").append(value).append("\r\n"); } } buf.append("\r\n"); } if (!writeResponse(trailer, ctx)) { // If keep-alive is off, close the connection once the content is fully written. ctx.writeAndFlush(Unpooled.EMPTY_BUFFER).addListener(ChannelFutureListener.CLOSE); } } } } private static void appendDecoderResult(StringBuilder buf, HttpObject o) { DecoderResult result = o.decoderResult(); if (result.isSuccess()) { return; } buf.append(".. WITH DECODER FAILURE: "); buf.append(result.cause()); buf.append("\r\n"); } private boolean writeResponse(HttpObject currentObj, ChannelHandlerContext ctx) { // Decide whether to close the connection or not. boolean keepAlive = HttpHeaders.isKeepAlive(request); // Build the response object. FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, currentObj.decoderResult().isSuccess() ? OK : BAD_REQUEST, Unpooled.copiedBuffer(buf.toString(), CharsetUtil.UTF_8)); response.headers().set(CONTENT_TYPE, "text/plain; charset=UTF-8"); if (keepAlive) { // Add 'Content-Length' header only for a keep-alive connection. response.headers().set(CONTENT_LENGTH, response.content().readableBytes()); // Add keep alive header as per: // - http://www.w3.org/Protocols/HTTP/1.1/draft-ietf-http-v11-spec-01.html#Connection response.headers().set(CONNECTION, HttpHeaders.Values.KEEP_ALIVE); } // Encode the cookie. String cookieString = request.headers().get(COOKIE); if (cookieString != null) { Set<Cookie> cookies = CookieDecoder.decode(cookieString); if (!cookies.isEmpty()) { // Reset the cookies if necessary. for (Cookie cookie : cookies) { response.headers().add(SET_COOKIE, ServerCookieEncoder.encode(cookie)); } } } else { // Browser sent no cookie. Add some. response.headers().add(SET_COOKIE, ServerCookieEncoder.encode("key1", "value1")); response.headers().add(SET_COOKIE, ServerCookieEncoder.encode("key2", "value2")); } // Write the response. ctx.write(response); return keepAlive; } private static void send100Continue(ChannelHandlerContext ctx) { FullHttpResponse response = new DefaultFullHttpResponse(HTTP_1_1, CONTINUE); ctx.write(response); } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { cause.printStackTrace(); ctx.close(); } }