Java tutorial
/* * MongoWP * Copyright 2014 8Kdata Technology (www.8kdata.com) * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package com.eightkdata.mongowp.server.wp; import static com.eightkdata.mongowp.messages.request.RequestOpCode.OP_DELETE; import static com.eightkdata.mongowp.messages.request.RequestOpCode.OP_GET_MORE; import static com.eightkdata.mongowp.messages.request.RequestOpCode.OP_INSERT; import static com.eightkdata.mongowp.messages.request.RequestOpCode.OP_KILL_CURSORS; import static com.eightkdata.mongowp.messages.request.RequestOpCode.OP_QUERY; import static com.eightkdata.mongowp.messages.request.RequestOpCode.OP_UPDATE; import com.eightkdata.mongowp.messages.request.DeleteMessage; import com.eightkdata.mongowp.messages.request.GetMoreMessage; import com.eightkdata.mongowp.messages.request.InsertMessage; import com.eightkdata.mongowp.messages.request.KillCursorsMessage; import com.eightkdata.mongowp.messages.request.QueryMessage; import com.eightkdata.mongowp.messages.request.RequestMessage; import com.eightkdata.mongowp.messages.request.RequestOpCode; import com.eightkdata.mongowp.messages.request.UpdateMessage; import com.eightkdata.mongowp.server.callback.MessageReplier; import com.eightkdata.mongowp.server.callback.RequestProcessor; import io.netty.channel.ChannelHandler; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelInboundHandlerAdapter; import io.netty.util.AttributeKey; import org.apache.logging.log4j.LogManager; import org.apache.logging.log4j.Logger; import javax.inject.Inject; /** * */ @ChannelHandler.Sharable public class RequestMessageObjectHandler extends ChannelInboundHandlerAdapter { private static final Logger LOGGER = LogManager.getLogger(RequestMessageObjectHandler.class); public static final AttributeKey<RequestOpCode> REQUEST_OP_CODE = AttributeKey.valueOf("requestOpCode"); private final RequestProcessor requestProcessor; @Inject public RequestMessageObjectHandler(RequestProcessor requestProcessor) { this.requestProcessor = requestProcessor; } @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { try (RequestMessage requestMessage = (RequestMessage) msg) { ctx.attr(NettyMessageReplier.REQUEST_ID).set(requestMessage.getBaseMessage().getRequestId()); LOGGER.debug("Received message type: {}, data: {}", requestMessage.getOpCode(), requestMessage); MessageReplier messageReplier = new NettyMessageReplier(ctx); ctx.attr(REQUEST_OP_CODE).set(requestMessage.getOpCode()); switch (requestMessage.getOpCode()) { case OP_QUERY: assert requestMessage instanceof QueryMessage; requestProcessor.queryMessage((QueryMessage) requestMessage, messageReplier); break; case OP_GET_MORE: assert requestMessage instanceof GetMoreMessage; requestProcessor.getMore((GetMoreMessage) requestMessage, messageReplier); break; case OP_KILL_CURSORS: assert requestMessage instanceof KillCursorsMessage; requestProcessor.killCursors((KillCursorsMessage) requestMessage, messageReplier); break; case OP_INSERT: assert requestMessage instanceof InsertMessage; requestProcessor.insert((InsertMessage) requestMessage, messageReplier); break; case OP_UPDATE: assert requestMessage instanceof UpdateMessage; requestProcessor.update((UpdateMessage) requestMessage, messageReplier); break; case OP_DELETE: assert requestMessage instanceof DeleteMessage; requestProcessor.delete((DeleteMessage) requestMessage, messageReplier); break; default: throw new UnsupportedOperationException( "Message replier not implemented for " + requestMessage.getOpCode() + " opCode"); } } } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { logCaughtException(cause); MessageReplier messageReplier = new NettyMessageReplier(ctx); requestProcessor.handleError(ctx.attr(REQUEST_OP_CODE).get(), messageReplier, cause); } private void logCaughtException(Throwable cause) { String message = "Error while processing request"; if (cause.getMessage() != null) { message += " (" + cause.getMessage() + ")"; } LOGGER.error(message, cause); } @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { try { LOGGER.info("Connection established from " + ctx.channel().remoteAddress()); } catch (Exception e) { LOGGER.debug("Exception raised while logging connection", e); } requestProcessor.onChannelActive(ctx); super.channelActive(ctx); } @Override public void channelInactive(ChannelHandlerContext ctx) throws Exception { try { LOGGER.info("Connection finished from " + ctx.channel().remoteAddress()); } catch (Exception e) { LOGGER.debug("Exception raised while logging disconnection", e); } super.channelInactive(ctx); requestProcessor.onChannelInactive(ctx); } }