/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2011, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* 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.
*
* [Oracle and Java are registered trademarks of Oracle and/or its affiliates.
* Other names may be trademarks of their respective owners.]
*
* -------------------------
* KeyedValueComparator.java
* -------------------------
* (C) Copyright 2003-2008, by Object Refinery Limited.
*
* Original Author: David Gilbert (for Object Refinery Limited);
* Contributor(s): -;
*
* Changes:
* --------
* 05-Mar-2003 : Version 1 (DG);
* 27-Aug-2003 : Moved SortOrder from org.jfree.data --> org.jfree.util (DG);
* 12-Jan-2005 : Added accessor methods (DG);
*
*/
package org.jfree.data;
import java.util.Comparator;
import org.jfree.util.SortOrder;
/**
* A utility class that can compare and order two {@link KeyedValue} instances
* and sort them into ascending or descending order by key or by value.
*/
public class KeyedValueComparator implements Comparator {
/** The comparator type. */
private KeyedValueComparatorType type;
/** The sort order. */
private SortOrder order;
/**
* Creates a new comparator.
*
* @param type the type (<code>BY_KEY</code> or <code>BY_VALUE</code>,
* <code>null</code> not permitted).
* @param order the order (<code>null</code> not permitted).
*/
public KeyedValueComparator(KeyedValueComparatorType type,
SortOrder order) {
if (order == null) {
throw new IllegalArgumentException("Null 'order' argument.");
}
this.type = type;
this.order = order;
}
/**
* Returns the type.
*
* @return The type (never <code>null</code>).
*/
public KeyedValueComparatorType getType() {
return this.type;
}
/**
* Returns the sort order.
*
* @return The sort order (never <code>null</code>).
*/
public SortOrder getOrder() {
return this.order;
}
/**
* Compares two {@link KeyedValue} instances and returns an
* <code>int</code> that indicates the relative order of the two objects.
*
* @param o1 object 1.
* @param o2 object 2.
*
* @return An int indicating the relative order of the objects.
*/
public int compare(Object o1, Object o2) {
if (o2 == null) {
return -1;
}
if (o1 == null) {
return 1;
}
int result;
KeyedValue kv1 = (KeyedValue) o1;
KeyedValue kv2 = (KeyedValue) o2;
if (this.type == KeyedValueComparatorType.BY_KEY) {
if (this.order.equals(SortOrder.ASCENDING)) {
result = kv1.getKey().compareTo(kv2.getKey());
}
else if (this.order.equals(SortOrder.DESCENDING)) {
result = kv2.getKey().compareTo(kv1.getKey());
}
else {
throw new IllegalArgumentException("Unrecognised sort order.");
}
}
else if (this.type == KeyedValueComparatorType.BY_VALUE) {
Number n1 = kv1.getValue();
Number n2 = kv2.getValue();
if (n2 == null) {
return -1;
}
if (n1 == null) {
return 1;
}
double d1 = n1.doubleValue();
double d2 = n2.doubleValue();
if (this.order.equals(SortOrder.ASCENDING)) {
if (d1 > d2) {
result = 1;
}
else if (d1 < d2) {
result = -1;
}
else {
result = 0;
}
}
else if (this.order.equals(SortOrder.DESCENDING)) {
if (d1 > d2) {
result = -1;
}
else if (d1 < d2) {
result = 1;
}
else {
result = 0;
}
}
else {
throw new IllegalArgumentException("Unrecognised sort order.");
}
}
else {
throw new IllegalArgumentException("Unrecognised type.");
}
return result;
}
}
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