cosort.java

用java实现的摄像头编程

/*
 * Version 0.70 01/04/2002
 *
 * Visit my url for update: http://www.geocities.com/beapetrovicova/
 * 
 * jFtp was developed by Bea Petrovicova <[e-mail]>.
 * The design and implementation of jFtp are available for royalty-free 
 * adoption and use. This software is provided 'as is' without any 
 * guarantees. Copyright is retained by Bea Petrovicova. Redistribution 
 * of any part of jFtp or any derivative works must include this notice.
 * 
 */  

package cz.dhl.io;

import java.util.Date;
import java.util.Vector;

/**
 * Orders, filters and splits arrays of CoFile objects.
 * 
 * @Version 0.70 01/04/2002
 * @author Bea Petrovicova <[e-mail]>  
 * @see CoFile
 */
public class CoSort
{  private int sorttype;
   
   /** Order Option - Order by name. */
   public static final int ORDER_BY_NAME = 1;
   /** Order Option - Order by extension. */
   public static final int ORDER_BY_TYPE = 2;
   /** Order Option - Order by size. */
   public static final int ORDER_BY_SIZE = 3;
   /** Order Option - Order by date. */
   public static final int ORDER_BY_DATE = 4;
   /** Order Option - Order by Path. */
   public static final int ORDER_BY_PATH = 5;
   /** Order Option - Skip ordering. */
   public static final int ORDER_BY_NONE = 6;
   /** Order Flag - Inverse flag. */
   public static final int ORDER_INVERSE = 8;   
   CoSort(int sorttype) 
      { this.sorttype = sorttype; }
   
   private boolean Pause() throws Exception { return true; }

   private void Swap(CoFile a[], int i, int j)
   {
      CoFile T;
      T = a[i]; 
      a[i] = a[j];
      a[j] = T;
   }

   private boolean AgreaterB(CoFile a,CoFile b)
   {  boolean compare = false; 
      switch(sorttype)
      {
      case ORDER_BY_NAME:
	 compare = (a.compareNameToIgnoreCase(b) > 0); break;
      case ORDER_BY_TYPE:
	 compare = (a.compareExtToIgnoreCase(b) > 0); break;
      case ORDER_BY_SIZE:
	 compare = (a.length() > b.length()); break;
      case ORDER_BY_DATE:
	 compare = (new Date(a.lastModified()).after(new Date(b.lastModified()))); break;
      case ORDER_BY_PATH:
         compare = (a.compareTo(b) > 0); break;
      } 
      return compare;
   }
   
   private boolean AsmallerB(CoFile a,CoFile b)
   {  boolean compare = false; 
      switch(sorttype)
      {
      case ORDER_BY_NAME:
	 compare = (a.compareNameToIgnoreCase(b) < 0); break;
      case ORDER_BY_TYPE:
	 compare = (a.compareExtToIgnoreCase(b) < 0); break;
      case ORDER_BY_SIZE:
	 compare = (a.length() < b.length()); break;
      case ORDER_BY_DATE:
	 compare = (new Date(a.lastModified()).before(new Date(b.lastModified()))); break;
      case ORDER_BY_PATH:
         compare = (a.compareTo(b) < 0); break;
      }
      return compare;
   }
   
   /** This is a generic version of C.A.R Hoare's Quick Sort 
    * algorithm.  This will handle arrays that are already
    * Sorted, and arrays with duplicate keys.
    * If you think of a one dimensional array as going from
    * the lowest index on the left to the highest index on the right
    * then the parameters to this function are lowest index or
    * left and highest index or right.  The first time you call
    * this function it will be with the parameters 0, a.length - 1.
    *
    * @param a       an CoFile array
    * @param lo0     left boundary of array partition
    * @param hi0     right boundary of array partition */
   private void QuickSort(CoFile a[], int lo0, int hi0) throws Exception
   {
      int lo = lo0;
      int hi = hi0;
      CoFile mid;

      if ( hi0 > lo0)
      {

         /* Arbitrarily establishing partition element as the midpoint of
          * the array. */
         mid = a[ ( lo0 + hi0 ) / 2 ];

         // loop through the array until indices cross
         while( lo <= hi )
         {
            /* find the first element that is greater than or equal to 
             * the partition element starting from the left Index. */
	     while( ( lo < hi0 ) && Pause() && AsmallerB(a[lo],mid))
		 ++lo;

            /* find an element that is smaller than or equal to 
             * the partition element starting from the right Index. */
	     while( ( hi > lo0 ) && Pause() && AgreaterB(a[hi],mid))
		 --hi;

            // if the indexes have not crossed, Swap
            if( lo <= hi ) 
            {
               Swap(a, lo, hi);
               ++lo;
               --hi;
            }
         }

         /* If the right index has not reached the left side of array
          * must now Sort the left partition. */
         if( lo0 < hi )
            QuickSort( a, lo0, hi );

         /* If the left index has not reached the right side of array
          * must now Sort the right partition. */
         if( lo < hi0 )
            QuickSort( a, lo, hi0 );

      }
   }

   private void Sort(CoFile a[]) throws Exception
   {  QuickSort(a, 0, a.length - 1); 
      if((sorttype&ORDER_INVERSE) > 0)
         for(int n=0; n<(a.length/2); n++)
            Swap(a, n, a.length-1-n);
   }

   /** Returns an array of abstract pathnames filtered by specified filter list. */
   static public CoFile[] listFilter(CoFile list[], String []filter)
   {  if(filter.length != 0)
      {  Vector ffv = new Vector(); 
	 for(int i=0;i<list.length;i++)
	    if(list[i].isDirectory() || 
	       list[i].isLink() ||
	       list[i].equalsExtTo(filter))
	       ffv.addElement(list[i]);
	 CoFile[] ffs = new CoFile[ffv.size()];
	 ffv.copyInto(ffs);
	 return ffs;
      } else return list;
   }

   /** Returns an array of abstract pathnames ordered by specified sorttype. */
   static public CoFile[] listOrder(CoFile list[], int sorttype) 
   {  if( (sorttype&(~ORDER_INVERSE)) != ORDER_BY_NONE)
      { CoSort s = new CoSort(sorttype);
	 try
	    { s.Sort(list); }
	 catch(Exception e)
	    {}
	 return list;
      } else return list;
   }
   
   /** Returns an array of abstract pathnames splited to directory and file part. */
   static public CoFile[] listSplit(CoFile list[])
   {  Vector ffv = new Vector(); 
      for(int i=0;i<list.length;i++)
	 if(list[i].isDirectory() || list[i].isLink())
	    ffv.addElement(list[i]); 
      for(int i=0;i<list.length;i++)
	 if(!list[i].isDirectory() && !list[i].isLink())
	    ffv.addElement(list[i]); 
      CoFile[] ffs = new CoFile[ffv.size()];
      ffv.copyInto(ffs);
      return ffs;
   }   
}