guid.java

P2P协议GUNTELLA的java源代码

/*
 * Copyright (C) 2000-2001  Ken McCrary
 *
 * 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
 *
 * Email: [e-mail]
 */
package com.kenmccrary.jtella;

import java.util.Arrays;
import java.util.zip.Adler32;

//import com.kenmccrary.jtella.util.UniqueIDGenerator;

/**
 *  Represents a unique ID
 *
 */
public class GUID
{
  private short[] data;

  /**
   *  Construct a new GUID
   *
   */
  public GUID()
  {
     data = Utilities.generateGUID();
  }


  /**
   *  Create a guid from network data
   *
   *
   */
  public GUID(short[] data)
  {
    this.data = data;
  }

  /**
   *  Query the bytes in this GUID
   *
   *  @return bytes
   */
  short[] getData()
  {
    return data;
  }

  /**
   *  Compare guids
   *
   */
  public boolean equals(Object obj)
  {
    if ( !(obj instanceof GUID) ) 
    {
      return false;
    }

    // Check if the data is the same
    GUID rhs = (GUID)obj;
    short[] lhsData = getData();
    short[] rhsData = rhs.getData();

    return Arrays.equals(lhsData, rhsData);
  }

  /**
   *  Produce a hashcode for this GUID
   *
   */
  public int hashCode() 
  {
    Adler32 adler32 = new Adler32();

    // todo fix this stuff
    byte[] tempData = new byte[data.length];

    for (int i = 0; i < data.length; i++) 
    {
      tempData[i] = (byte)data[i];
    }

    adler32.update(tempData);

    return (int)adler32.getValue();
  }

  /**
   *  Returns a GUID as a String
   *
   *  @return text form of guid
   */
  public String toString()
  {
    StringBuffer message = new StringBuffer();
    message.append("GUID: ");

    for (int i = 0; i < data.length; i++) 
    {
      message.append( "[" +
                      Integer.toHexString( data[i]) +
                      "]");
    }

    return message.toString();
  }
}