CamelUdpNettyHandler.java

/*
 * 
 * Copyright (C) 2012-2014 R T Huitema. All Rights Reserved.
 * Web: www.42.co.nz
 * Email: robert@42.co.nz
 * Author: R T Huitema
 * 
 * This file is part of the signalk-server-java project
 * 
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 * 
 * Licensed 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 nz.co.fortytwo.signalk.server;

import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.socket.DatagramPacket;
import io.netty.channel.socket.nio.NioDatagramChannel;
import io.netty.util.CharsetUtil;

import java.net.InetSocketAddress;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;

import mjson.Json;
import nz.co.fortytwo.signalk.util.ConfigConstants;
import nz.co.fortytwo.signalk.util.SignalKConstants;
import nz.co.fortytwo.signalk.util.Util;

import org.apache.camel.ProducerTemplate;
import org.apache.camel.component.websocket.WebsocketConstants;
import org.apache.camel.impl.DefaultProducerTemplate;
import org.apache.logging.log4j.LogManager; import org.apache.logging.log4j.Logger;

import com.google.common.collect.BiMap;
import com.google.common.collect.HashBiMap;


@Sharable
public class CamelUdpNettyHandler extends SimpleChannelInboundHandler<DatagramPacket> {

	private Logger logger = LogManager.getLogger(CamelUdpNettyHandler.class);
	private BiMap<String,InetSocketAddress> sessionList = HashBiMap.create();
	
	ProducerTemplate producer;

	private String outputType;
	
	
	public CamelUdpNettyHandler( String outputType) throws Exception {
		this.outputType=outputType;
		producer= new DefaultProducerTemplate(CamelContextFactory.getInstance());
		producer.setDefaultEndpointUri(RouteManager.SEDA_INPUT );
		producer.start();
	}

	@Override
	public void channelActive(ChannelHandlerContext ctx) throws Exception {
		// Send greeting for a new connection.
		NioDatagramChannel udpChannel = (NioDatagramChannel) ctx.channel();
		if(logger.isDebugEnabled())logger.debug("channelActive:" + udpChannel.localAddress());
		
	}

	@Override
	protected void channelRead0(ChannelHandlerContext ctx, DatagramPacket packet) throws Exception {
		String request = packet.content().toString(CharsetUtil.UTF_8);
		if(logger.isDebugEnabled())logger.debug("Sender "+packet.sender()+" sent request:" + request);

		if(!sessionList.inverse().containsKey(packet.sender())){
			String session = UUID.randomUUID().toString();
			String localAddress = ctx.channel().localAddress().toString();
			String remoteAddress = ctx.channel().remoteAddress().toString();
			SubscriptionManagerFactory.getInstance().add(session, session, outputType, localAddress, remoteAddress);
			sessionList.put(session, packet.sender());
			if(logger.isDebugEnabled())logger.debug("Added Sender "+packet.sender()+", session:" + session);
			ctx.channel().writeAndFlush(new DatagramPacket(
					Unpooled.copiedBuffer(Util.getWelcomeMsg().toString() + "\r\n", CharsetUtil.UTF_8),packet.sender()));
		}
		
		Map<String, Object> headers = getHeaders(sessionList.inverse().get(packet.sender()));
		producer.sendBodyAndHeaders(request, headers);
	}

	@Override
	public void channelReadComplete(ChannelHandlerContext ctx) {
		ctx.flush();
	}

	@Override
	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
		cause.printStackTrace();
		ctx.close();
	}

	@Override
	public boolean acceptInboundMessage(Object msg) throws Exception {
		if(msg instanceof Json || msg instanceof String)return true;
		return super.acceptInboundMessage(msg);
	}

	private Map<String, Object> getHeaders(String wsSession) {
		Map<String, Object> headers = new HashMap<>();
		headers.put(WebsocketConstants.CONNECTION_KEY, wsSession);
		headers.put(SignalKConstants.MSG_SRC_IP, sessionList.get(wsSession).getHostString());
		headers.put(SignalKConstants.MSG_SRC_BUS, "udp."+sessionList.get(wsSession).getHostString().replace('.', '_'));
		headers.put(ConfigConstants.OUTPUT_TYPE, outputType);
		return headers;
	}

	protected BiMap<String, InetSocketAddress> getSessionList() {
		return sessionList;
	}
}