/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.test.client.ctc;
import java.util.List;
/**
* This class can be used for comparing lists of elements, when the fields to
* be sorted on and the comparison mechanism are dynamically specified. <p>
*
* Typically, the lists are records in a collection that is to be sorted. <p>
*
* <h3>Example</h3>
* <pre>
* Records...
* { "a1", "b1", "c1" }
* { "a1", "b1", "c2" }
* { "a1", "b2", "c1" }
* { "a1", "b2", "c2" }
* { "a2", "b1", "c1" }
* { "a2", "b1", "c2" }
* { "a2", "b2", "c1" }
* { "a2", "b2", "c2" }
*
* Records sorted in ascending order on columns 0, 2...
* { "a1", "b1", "c1" }
* { "a1", "b2", "c1" }
* { "a1", "b2", "c2" }
* { "a1", "b1", "c2" }
* { "a2", "b1", "c1" }
* { "a2", "b2", "c1" }
* { "a2", "b1", "c2" }
* { "a2", "b2", "c2" }
* </pre>
*/
public class ListNestedSortComparator implements java.util.Comparator, java.io.Serializable {
/**
* Specifies which fields to sort on.
*/
private int[] sortParameters;
/**
* Indicates whether comparison should be based on ascending or descending
* order.
*/
private boolean ascendingOrder = false;
/**
* List of booleans indicating the order in which each column should be sorted
*/
private List orderTypes = null;
private boolean isDistinct = true;
private int distinctIndex;
/**
* Constructs an instance of this class given the indicies of the parameters
* to sort on, and whether the sort should be in ascending or descending
* order.
*/
public ListNestedSortComparator( int[] sortParameters ) {
this( sortParameters, false );
}
/**
* Constructs an instance of this class given the indicies of the parameters
* to sort on, and whether the sort should be in ascending or descending
* order.
*/
public ListNestedSortComparator( int[] sortParameters, boolean ascending ) {
this.sortParameters = sortParameters;
this.ascendingOrder = ascending;
}
/**
* Constructs an instance of this class given the indicies of the parameters
* to sort on, and orderList used to determine the order in which each column
* is sorted.
*/
public ListNestedSortComparator( int[] sortParameters, List orderTypes ) {
this.sortParameters = sortParameters;
this.orderTypes = orderTypes;
}
public boolean isDistinct() {
return isDistinct;
}
public void setDistinctIndex(int distinctIndex) {
this.distinctIndex = distinctIndex;
}
/**
* Compares its two arguments for order. Returns a negative integer,
* zero, or a positive integer as the first argument is less than,
* equal to, or greater than the second. <p>
*
* The <code>compare</code> method returns <p>
* <ul>
* <li>-1 if object1 less than object 2 </li>
* <li> 0 if object1 equal to object 2 </li>
* <li>+1 if object1 greater than object 2 </li>
* </ul>
*
* @param o1 The first object being compared
* @param o2 The second object being compared
*/
public int compare( Object o1, Object o2 ) {
List list1 = (List)o1;
List list2 = (List)o2;
int compare = 0;
for (int k = 0; k < sortParameters.length; k++) {
Object param1 = list1.get(sortParameters[k]);
Object param2 = list2.get(sortParameters[k]);
if( param1 == null ) {
if(param2 == null ) {
// Both are null
compare = 0;
} else {
// param1 = null, so is less than a non-null
compare = -1;
}
} else if( param2 == null ) {
// param1 != null, param2 == null
compare = 1;
} else if ( param1 instanceof Comparable ) {
compare = ((Comparable)param1).compareTo(param2);
} else {
compare = 0;
}
if (compare != 0) {
boolean asc = orderTypes != null?((Boolean)orderTypes.get(k)).booleanValue():this.ascendingOrder;
return asc ? compare : -compare;
} else if (k == distinctIndex) {
isDistinct = false;
}
}
return 0;
}
} // END CLASS