/**
* Licensed under the Artistic License; you may not use this file
* except in compliance with the License.
* You may obtain a copy of the License at
*
* http://displaytag.sourceforge.net/license.html
*
* THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
package org.displaytag.model;
import java.util.Comparator;
import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
import org.displaytag.decorator.TableDecorator;
import org.displaytag.exception.ObjectLookupException;
import org.displaytag.exception.RuntimeLookupException;
import org.displaytag.util.LookupUtil;
/**
* Comparator for rows.
* @author Fabrizio Giustina
* @version $Revision: 923 $ ($Author: fgiust $)
*/
public class RowSorter implements Comparator
{
/**
* name of the property in bean.
*/
private String property;
/**
* table decorator.
*/
private TableDecorator decorator;
/**
* sort order ascending?
*/
private boolean ascending;
/**
* Index of the sorted column.
*/
private int columnIndex;
/**
* Comparator used for comparisons.
*/
private Comparator comparator;
/**
* Initialize a new RowSorter.
* @param sortedColumnIndex index of the sorted column
* @param beanProperty name of the property. If pProperty is null column index is used to get a static cell value
* from the row object
* @param tableDecorator TableDecorator instance
* @param ascendingOrder boolean ascending order?
* @param compar the comparator to use
*/
public RowSorter(
int sortedColumnIndex,
String beanProperty,
TableDecorator tableDecorator,
boolean ascendingOrder,
Comparator compar)
{
this.columnIndex = sortedColumnIndex;
this.property = beanProperty;
this.decorator = tableDecorator;
this.ascending = ascendingOrder;
this.comparator = compar;
}
/**
* Compares two objects by first fetching a property from each object and then comparing that value. If there are
* any errors produced while trying to compare these objects then a RunTimeException will be thrown as any error
* found here will most likely be a programming error that needs to be quickly addressed (like trying to compare
* objects that are not comparable, or trying to read a property from a bean that is invalid, etc...)
* @param object1 Object
* @param object2 Object
* @return int
* @see java.util.Comparator#compare(Object, Object)
*/
public final int compare(Object object1, Object object2)
{
Object obj1 = null;
Object obj2 = null;
// if property is null compare using two static cell objects
if (this.property == null)
{
if (object1 instanceof Row)
{
obj1 = ((Row) object1).getCellList().get(this.columnIndex);
}
if (object2 instanceof Row)
{
obj2 = ((Row) object2).getCellList().get(this.columnIndex);
}
return checkNullsAndCompare(obj1, obj2);
}
if (object1 instanceof Row)
{
obj1 = ((Row) object1).getObject();
}
if (object2 instanceof Row)
{
obj2 = ((Row) object2).getObject();
}
try
{
Object result1;
Object result2;
// If they have supplied a decorator, then make sure and use it for the sorting as well
if (this.decorator != null && this.decorator.hasGetterFor(this.property))
{
// set the row before sending to the decorator
this.decorator.initRow(obj1, 0, 0);
result1 = LookupUtil.getBeanProperty(this.decorator, this.property);
// set the row before sending to the decorator
this.decorator.initRow(obj2, 0, 0);
result2 = LookupUtil.getBeanProperty(this.decorator, this.property);
}
else
{
result1 = LookupUtil.getBeanProperty(obj1, this.property);
result2 = LookupUtil.getBeanProperty(obj2, this.property);
}
return checkNullsAndCompare(result1, result2);
}
catch (ObjectLookupException e)
{
throw new RuntimeLookupException(getClass(), this.property, e);
}
}
/**
* Compares two given objects, and handles the case where nulls are present.
* @param object1 first object to compare
* @param object2 second object to compare
* @return int result
*/
private int checkNullsAndCompare(Object object1, Object object2)
{
int returnValue;
if (object1 == null && object2 != null)
{
returnValue = -1;
}
else if (object1 != null && object2 == null)
{
returnValue = 1;
}
else if (object1 == null && object2 == null)
{
// both null
returnValue = 0;
}
else
{
returnValue = comparator.compare(object1, object2);
}
int ascendingInt = this.ascending ? 1 : -1;
return ascendingInt * returnValue;
}
/**
* Is this Comparator the same as another one?
* @param object Object
* @return boolean
* @see java.util.Comparator#equals(Object)
*/
public final boolean equals(Object object)
{
if (object instanceof RowSorter)
{
return new EqualsBuilder().append(this.property, ((RowSorter) object).property).append(
this.columnIndex,
((RowSorter) object).columnIndex).isEquals();
}
return false;
}
/**
* @see java.lang.Object#hashCode()
*/
public final int hashCode()
{
return new HashCodeBuilder(31, 33).append(this.property).append(this.columnIndex).toHashCode();
}
}