org.norther.tammi.acorn.util
Class PropertyComparator

java.lang.Object
  org.norther.tammi.acorn.util.PropertyComparator

All Implemented Interfaces:

Serializable, Comparator<Object>

Direct Known Subclasses:

VariableComparator

public class PropertyComparator
extends Object
implements Comparator<Object>, Serializable

A comparator for properties.

Version:

$Id: PropertyComparator.java,v 1.11 2009/09/28 15:08:49 cvsimp Exp $

Author:

Ilkka Priha

See Also:

Serialized Form

Constructor Summary

PropertyComparator(String prop)
Constructs a new comparator.

PropertyComparator(String[] props)
Constructs a new comparator for multiple properties.

PropertyComparator(String[] props, Comparator<?> comp)
Constructs a new comparator for multiple properties with a value comparator.

PropertyComparator(String prop, Comparator<?> comp)
Constructs a new comparator with a value comparator.

Method Summary

int	compare(Object obj1, Object obj2)
protected int	compare(Object var1, Object var2, String prop) Compares the specified property of two objects in ascending order.
protected Object	getNestedProperty(Object obj, String prop) Gets the optionally nested property value.
protected Object	getProperty(Object obj, String prop) Gets the named property value.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Comparator

equals

Constructor Detail

PropertyComparator

public PropertyComparator(String prop)

Constructs a new comparator.

Parameters:

prop - the property to compare.

PropertyComparator

public PropertyComparator(String prop,
                          Comparator<?> comp)

Constructs a new comparator with a value comparator.

Parameters:

prop - the property to compare.

comp - the property value comparator.

PropertyComparator

public PropertyComparator(String[] props)

Constructs a new comparator for multiple properties.

Parameters:

props - the properties to compare.

PropertyComparator

public PropertyComparator(String[] props,
                          Comparator<?> comp)

Constructs a new comparator for multiple properties with a value comparator.

Parameters:

props - the properties to compare.

comp - the property value comparator.

Method Detail

compare

public int compare(Object obj1,
                   Object obj2)

Specified by:

compare in interface Comparator<Object>

compare

protected int compare(Object var1,
                      Object var2,
                      String prop)

Compares the specified property of two objects in ascending order.

Parameters:

var1 - the first object to be compared.

var2 - the second object to be compared.

prop - the name of the property.

Returns:

-1, 0 or 1 based on comparison.

getNestedProperty

protected Object getNestedProperty(Object obj,
                                   String prop)
                            throws Exception

Gets the optionally nested property value.

Parameters:

obj - the object.

prop - the property.

Returns:

the value or null.

Throws:

Exception - on errors.

getProperty

protected Object getProperty(Object obj,
                             String prop)
                      throws Exception

Gets the named property value.

Parameters:

obj - the object.

prop - the property.

Returns:

the value or null.

Throws:

Exception - on errors.