it.jnrpe.net.JNRPERequestDecoder Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of jnrpe-lib Show documentation
A library that implements the NRPE protocol for JAVA applications
The newest version!
/*******************************************************************************
 * Copyright (c) 2007, 2014 Massimiliano Ziccardi
 *
 * 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 it.jnrpe.net;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.ReplayingDecoder;

import java.util.List;

import org.apache.commons.lang.ArrayUtils;

/**
 * The NETTY implementation of the JNRPE protocol request decoder.
 * 
 * @author Massimiliano Ziccardi
 * @version $Revision: 1.0 $
 */
public class JNRPERequestDecoder extends ReplayingDecoder {

    /**
     * The packet buffer length in bytes.
     */
    private static final int PACKETBUFFER_LENGTH = 1024;

    /**
     * The size of the random byte array.
     */
    private static final int DUMMYLENGTH = 2;

    /**
     * The decoded protocol packet.
     */
    private JNRPEProtocolPacket packet;

    /**
     * The decoded packet version.
     */
    private PacketVersion packetVersion;

    /**
     * The NETTY {@link ReplayingDecoder} will be called many times until all
     * the data has been received from the server. This enum will be used to
     * store the decoding process progress.
     * 
     * @author Massimiliano Ziccardi
     */
    protected enum STAGE {
        /**
         * The next data we have to receive is the PACKET_VERSION.
         */
        PACKET_VERSION,
        /**
         * The next data we have to receive is the REQUST TYPE CODE.
         */
        PACKET_TYPE_CODE,
        /**
         * The next data we have to receive is the request CRC.
         */
        CRC,
        /**
         * The next data we have to receive is the RESULT CODE.
         */
        RESULT_CODE,
        /**
         * The next data we have to receive is DATA BUFFER.
         */
        BUFFER,
        /**
         * The next data we have to receive is DUMMY buffer.
         */
        DUMMY
    };

    /**
     * Creates a new {@link JNRPERequestDecoder} object and sets the initial
     * state at {@link STAGE#PACKET_VERSION}.
     */
    public JNRPERequestDecoder() {
        super(STAGE.PACKET_VERSION);
    }

    /**
     * Method decode.
     * @param ctx ChannelHandlerContext
     * @param in ByteBuf
     * @param out List