org.bgp4j.netty.protocol.BGPv4Packet.java Source code

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Here is the source code for org.bgp4j.netty.protocol.BGPv4Packet.java

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/**
 *  Copyright 2012 Rainer Bieniek (Rainer.Bieniek@web.de)
 *
 *  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.bgp4j.netty.protocol;

import io.netty.buffer.ByteBuf;

import org.apache.commons.lang3.builder.ToStringBuilder;
import org.bgp4j.netty.BGPv4Constants;

/**
 * base class for all BGPv4 protocol packets
 * 
 * @author Rainer Bieniek (Rainer.Bieniek@web.de)
 *
 */
public abstract class BGPv4Packet {
    /**
     * build a binary representation of the protocol packet
     * 
     * @param buffer The buffer to store the binary packet representation into
     */
    public void encodePacket(ByteBuf buffer) {
        for (int i = 0; i < BGPv4Constants.BGP_PACKET_MARKER_LENGTH; i++)
            buffer.writeByte(0xff);

        int headerHeaderIndex = buffer.writerIndex();

        buffer.writeShort(BGPv4Constants.BGP_PACKET_HEADER_LENGTH);

        buffer.writeByte(getType());
        encodePayload(buffer);

        buffer.setShort(headerHeaderIndex,
                BGPv4Constants.BGP_PACKET_HEADER_LENGTH + (buffer.writerIndex() - headerHeaderIndex) - 3);
    }

    /**
     * encode the specific packet-type payload
     * 
     * @return the encoded packet payload
     */
    protected abstract void encodePayload(ByteBuf buffer);

    /**
     * obtain the BGP packet type code.
     * 
     * @return
     */
    public abstract int getType();

    @Override
    public String toString() {
        return (new ToStringBuilder(this)).append("type", getType()).toString();
    }
}