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 metricsdb.core.http; 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.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.DefaultHttpRequest; 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 java.io.Reader; import java.io.InputStreamReader; import java.io.InputStream; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.UnsupportedEncodingException; import java.nio.charset.StandardCharsets; import static io.netty.handler.codec.http.HttpHeaders.Names.*; import static io.netty.handler.codec.http.HttpHeaders.*; import static io.netty.handler.codec.http.HttpResponseStatus.*; import static io.netty.handler.codec.http.HttpVersion.*; import java.util.logging.Logger; import java.util.logging.ConsoleHandler; import java.util.logging.SimpleFormatter; import java.util.logging.Level; import metricsdb.core.*; import metricsdb.core.json.*; import metricsdb.core.datastores.*; public class HttpSnoopServerHandler extends SimpleChannelInboundHandler<Object> { /** Buffer that stores the response content */ private final StringBuilder buf = new StringBuilder(); private static final Logger logger = Logger.getLogger(HttpSnoopServerHandler.class.getName()); private HttpRequest httpRequest; private String json; private DataStore dataStore; private Reader reader; private String uri; @Override public void channelReadComplete(ChannelHandlerContext ctx) throws Exception { ctx.flush(); } @Override protected void channelRead0(ChannelHandlerContext ctx, Object msg) { setupLogger(); handleHttpRequest(ctx, msg); } private void setupLogger() { logger.setLevel(Level.ALL); ConsoleHandler handler = new ConsoleHandler(); handler.setFormatter(new SimpleFormatter()); handler.setLevel(Level.ALL); logger.addHandler(handler); } private void handleHttpRequest(ChannelHandlerContext ctx, Object msg) { if (msg instanceof HttpRequest) { this.httpRequest = (HttpRequest) msg; } if (msg instanceof HttpContent) { HttpContent httpContent = (HttpContent) msg; ByteBuf content = httpContent.content(); this.json = content.toString(CharsetUtil.UTF_8); this.uri = httpRequest.getUri(); try { reader = createInputStream(json); } catch (IOException e) { logger.info("Cannot create reader object"); } JsonParser jsonParser = new JsonParser(reader); dataStore = new MetricsDB(); //JsonParserBuilder jsonBuilder = new JsonParserBuilder(jsonParser); RequestFactory requestFactory = new RequestFactory(jsonParser, dataStore); Request request = requestFactory.createRequest(uri); String response = request.execute(); } if (msg instanceof LastHttpContent) { LastHttpContent trailer = (LastHttpContent) msg; writeResponse(trailer, ctx); } } private Reader createInputStream(String json) throws UnsupportedEncodingException { InputStream jsonStream = new ByteArrayInputStream(json.getBytes(StandardCharsets.UTF_8)); return new InputStreamReader(jsonStream, "UTF-8"); } private boolean writeResponse(HttpObject currentObj, ChannelHandlerContext ctx) { // Decide whether to close the connection or not. boolean keepAlive = isKeepAlive(httpRequest); // Build the response object. 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) { // 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 = httpRequest.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) throws Exception { cause.printStackTrace(); ctx.close(); } }