ResponseEncoder.java

/*
 * Copyright 2014-2016 CyberVision, Inc.
 *
 * 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 org.kaaproject.kaa.server.transports.http.transport.netty;

import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelOutboundHandlerAdapter;
import io.netty.channel.ChannelPromise;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpResponse;
import io.netty.util.Attribute;

import org.kaaproject.kaa.server.common.server.AbstractNettyServer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.UUID;


/**
 * ResponseEncoder Class.
 * Used to convert CommandProcressor after execution into HTTP response
 * and set Netty channel to close in case it indicated by CommandProcessor.
 *
 * @author Andrey Panasenko
 */
public class ResponseEncoder extends ChannelOutboundHandlerAdapter {

  private static final Logger LOG = LoggerFactory.getLogger(ResponseEncoder.class);

  @Override
  public void write(ChannelHandlerContext ctx, Object msg,
                    ChannelPromise promise) throws Exception {
    Attribute<UUID> sessionUuidAttr = ctx.channel().attr(AbstractNettyServer.UUID_KEY);

    if (!(msg instanceof AbstractCommand)) {
      LOG.warn("Session [{}] got invalid HTTP response: {}", sessionUuidAttr, msg);
      super.write(ctx, msg, promise);
      return;
    } else {
      LOG.trace("Session [{}] got valid HTTP response: {}", sessionUuidAttr, msg);
    }

    AbstractCommand cp = (AbstractCommand) msg;

    HttpResponse httpResponse = cp.getResponse();

    ChannelFuture future = ctx.writeAndFlush(httpResponse, promise);
    if (!HttpHeaders.isKeepAlive(httpResponse)) {
      future.addListener(ChannelFutureListener.CLOSE);
    }
  }
}