Tlv.java :  » App » android-chatty » ru » caffeineim » protocols » icq » Android Open Source

/**
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.

 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.

 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package ru.caffeineim.protocols.icq;

/**
 * <p>Created by
 *   @author Fabrice Michellonet
 *   @author   (aleks_dsp)
 */
public class Tlv extends DataContainer {

  private static final int TLV_HEADER_SIZE = 4;

  private RawData type;
  private RawData length;

  private byte[] headerByteArray;

  /**
   * Create a TLV which value isn't defined at creation.
   * Based on Onix's code.
   * @param type The Tlv's type.
   */
  public Tlv(int type) {
    headerByteArray = new byte[TLV_HEADER_SIZE];
    /* Setting type */
    this.type = new RawData(type, RawData.WORD_LENGTH);
  }

  public Tlv(RawData value, int tlvType) {
    this(tlvType);
    /* Setting the value */
    appendRawDataToTlv(value);
  }

  public Tlv(Tlv value, int tlvType){
    this(tlvType);
    /* Setting the value */
    appendTlvToTlv(value);
  }

  /**
   * Create a TLV containing a String.
   *
   * @param string The TLV's String.
   * @param tlvType The TLV's type.
   */
  public Tlv(String string, int tlvType) {
    this(new RawData(string), tlvType);
  }

  /**
   * Create a TLV containing a numeric value.
   *
   * @param val The TLV's numeric value.
   * @param tlvType The TLV's type.
   */
  public Tlv(int val, int tlvType) {
    this(new RawData(val), tlvType);
  }

  /**
   *
   * @param val The TLV's numeric value.
   * @param forcedLENGTH The type of variable.
   * @param tlvType The TLV's type.
   */
  public Tlv(int val, int forcedLENGTH, int tlvType) {
    this(new RawData(val, forcedLENGTH), tlvType);
  }

  public Tlv(byte[] array, int start) {
    headerByteArray = new byte[TLV_HEADER_SIZE];
    headerModified = true;
    byte[] typeArray = new byte[2];
    byte[] lengthArray = new byte[2];
    byte[] valueArray;

    System.arraycopy(array, start, typeArray, 0, 2);
    this.type = new RawData(typeArray);
    System.arraycopy(array, start + 2, lengthArray, 0, 2);
    this.length = new RawData(lengthArray);
    valueArray = new byte[getLength()];
    System.arraycopy(array, start + 4, valueArray, 0, getLength());
    appendRawDataToTlv(new RawData(valueArray));
  }

  public void appendRawDataToTlv(RawData data) {
    addDataField(data);
  }

  public void appendTlvToTlv(Tlv tlv) {
    addDataField(tlv);
  }

  public byte[] getHeaderByteArray() {
    if (headerModified) {
      /* computing dataFieldLength field */
      length = new RawData(getDataFieldByteArray().length, RawData.WORD_LENGTH);
      /* adding type field array */
      System.arraycopy(type.getByteArray(), 0, headerByteArray, 0,
          type.getByteArray().length);
      /* adding LENGTH field array */
      System.arraycopy(length.getByteArray(), 0, headerByteArray, 2,
          length.getByteArray().length);
      headerModified = false;
    }
    
    return headerByteArray;
  }

  /**
   * @return The TLV's type.
   */
  public int getType() {
    return type.getValue();
  }

  /**
   * @return The TLV's length.
   */
  public int getLength() {
    return length.getValue();
  }

  /**
   * @return The TLV's value.
   */
  public int getValue() {
    return ( (RawData) elementAt(0)).getValue();
  }

  /**
   * @return The TLV's String value.
   */
  public String getStringValue() {
    return ( (RawData) elementAt(0)).getStringValue();
  }
}