Disconnect.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.common.channels.protocols.kaatcp.messages;

import org.kaaproject.kaa.common.channels.protocols.kaatcp.KaaTcpProtocolException;

/**
 * Disconnect message Class. The DISCONNECT message is sent from the client to the server to
 * indicate that it is about to close its TCP/IP connection. This provides a clean disconnection,
 * rather than just dropping the line. If the client had connected with the clean session flag set,
 * then all previously maintained information about the client will be discarded. A server should
 * not rely on the client to close the TCP/IP connection after receiving a DISCONNECT.
 *
 * @author Andrey Panasenko
 */
public class Disconnect extends MqttFrame {

  public static final int DISCONNECT_REMAINING_LEGTH_V1 = 2;
  private DisconnectReason reason;

  /**
   * Default constructor.
   *
   * @param reason the reason
   */
  public Disconnect(DisconnectReason reason) {
    setMessageType(MessageType.DISCONNECT);
    setReason(reason);
    remainingLength = DISCONNECT_REMAINING_LEGTH_V1;
  }

  /**
   * Default Constructor.
   */
  public Disconnect() {
    setMessageType(MessageType.DISCONNECT);
  }

  /**
   * Return Disconnect reason.
   *
   * @return byte reason
   */
  public DisconnectReason getReason() {
    return reason;
  }

  /**
   * Set Disconnect reason.
   *
   * @param reason DisconnectReason
   */
  public void setReason(DisconnectReason reason) {
    this.reason = reason;
  }

  /* (non-Javadoc)
   * @see org.kaaproject.kaa.common.channels.protocols.kaatcp.messages.mqttFrame#pack(int)
   */
  @Override
  protected void pack() {
    buffer.put((byte) 0);
    buffer.put(reason.getReason());
  }

  /* (non-Javadoc)
   * @see org.kaaproject.kaa.common.channels.protocols.kaatcp.messages.mqttFrame#decode()
   */
  @Override
  protected void decode() throws KaaTcpProtocolException {
    byte code = buffer.get(1);
    for (DisconnectReason tmp : DisconnectReason.values()) {
      if (code == tmp.getReason()) {
        reason = tmp;
        return;
      }
    }
    throw new KaaTcpProtocolException("Unknown disconnect reason!");
  }

  /* (non-Javadoc)
   * @see
   * org.kaaproject.kaa.common.channels.protocols.kaatcp.messages.MqttFrame#isNeedCloseConnection()
   */
  @Override
  public boolean isNeedCloseConnection() {
    return true;
  }

  /**
   * DISCONNECT             return code     reason.
   * NONE                   0x00            No error
   * BAD_REQUEST            0x01            Client sent a corrupted data
   * INTERNAL_ERROR         0x02            Internal error has been occurred
   */
  public enum DisconnectReason {
    NONE((byte) 0x00),
    BAD_REQUEST((byte) 0x01),
    INTERNAL_ERROR((byte) 0x02),
    CREDENTIALS_REVOKED((byte) 0x03);

    private byte reason;

    private DisconnectReason(byte code) {
      this.reason = code;
    }

    /**
     * Return byte representation of ConnAck return code.
     *
     * @return byte returnCode
     */
    public byte getReason() {
      return reason;
    }

  }

}