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JETT is a Java API that reads an Excel spreadsheet as a template, takes your data, and creates a new Excel spreadsheet that contains your data, formatted as in the template. It works with .xls and .xlsx template spreadsheets.

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package net.sf.jett.util;

import java.util.Comparator;
import java.util.List;

import net.sf.jett.exception.ParseException;
import net.sf.jett.model.Group;

/**
 * A GroupOrderByComparator is an OrderByComparator
 * that operates on groups and understands that some of the "order by"
 * properties are group properties (these must all be before the other "order
 * by" properties that aren't group properties).
 *
 * @author Randy Gettman
 * @since 0.3.0
 */
public class GroupOrderByComparator implements Comparator
{
   private OrderByComparator myOrderByComparator;
   private List myGroupByProperties;

   /**
    * Constructs a GroupOrderByComparator that operates on the
    * given List of "order by" expressions, and assumes that the
    * Groups are grouped by the given List of "group
    * by" expressions.
    * @param orderByComparator An OrderByComparator.
    * @param groupByProperties A List of "group by" properties.
    * @throws ParseException If there is a problem parsing the expressions, or
    *    if any "group by" properties are preceded in the "order by" properties
    *    by other properties that are not "group by" properties.
    */
   public GroupOrderByComparator(OrderByComparator orderByComparator, List groupByProperties)
   {
      myOrderByComparator = orderByComparator;
      myGroupByProperties = groupByProperties;
      ensureOrderByGroupByLegal();
   }

   /**
    * Ensures that no "order by" properties are before any "group by"
    * properties in the expressions list.
    * @throws ParseException If any "group by" properties are preceded in the
    *    "order by" properties by other properties that are not "group by"
    *    properties.
    */
   private void ensureOrderByGroupByLegal()
   {
      boolean foundOrderByNotInGroupBy = false;
      boolean orderByInGroupBy;
      List orderByProperties = myOrderByComparator.getProperties();
      for (String orderBy : orderByProperties)
      {
         orderByInGroupBy = myGroupByProperties.contains(orderBy);
         if (foundOrderByNotInGroupBy)
         {
            if (!orderByInGroupBy)
               throw new ParseException("The \"order by\" property \"" + orderBy +
                  "\" is in the \"group by\" properties (" + myGroupByProperties.toString() +
                  "), but it must not follow other \"order by\" properties (" +
                  orderByProperties.toString() + ") that aren't \"group by\" properties.");
         }
         else
         {
            // Set flag indicating that all further "order by" properties must
            // NOT be a "group by" property.
            if (!orderByInGroupBy)
               foundOrderByNotInGroupBy = true;
         }
      }
   }

   /**
    * 
Compares the given Groups to determine order.  Fulfills
    * the Comparator contract by returning a negative integer, 0,
    * or a positive integer if o1 is less than, equal to, or
    * greater than o2.

    * 
This compare method compares the group's representative objects.

    *
    * @param g1 The left-hand-side Group to compare.
    * @param g2 The right-hand-side Group to compare.
    * @return A negative integer, 0, or a positive integer if g1
    *    is less than, equal to, or greater than g2.
    * @throws UnsupportedOperationException If any property specified in the
    *    constructor doesn't correspond to a no-argument "get<Property>"
    *    getter method in T, or if the property's type is not
    *    Comparable.
    */
   public int compare(T g1, T g2)
   {
      return myOrderByComparator.compare(g1.getObj(), g2.getObj());
   }

   /**
    * Returns the List of "group by" properties.
    * @return The List of "group by" properties.
    */
   public List getGroupByProperties()
   {
      return myGroupByProperties;
   }
}
    

    

    
            
    
            







    
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