org.springframework.core

Class OrderComparator

java.lang.Object

org.springframework.core.OrderComparator

All Implemented Interfaces:

Comparator<Object>

Direct Known Subclasses:

AnnotationAwareOrderComparator

public class OrderComparator
extends Object
implements Comparator<Object>

Comparator implementation for Ordered objects, sorting by order value ascending (resp. by priority descending).

Non-Ordered objects are treated as greatest order values, thus ending up at the end of the list, in arbitrary order (just like same order values of Ordered objects).

Since:

07.04.2003

Author:

Juergen Hoeller

See Also:

Ordered, Collections.sort(java.util.List, java.util.Comparator), Arrays.sort(Object[], java.util.Comparator)

Field Summary

Fields

Modifier and Type	Field and Description
static OrderComparator	INSTANCE Shared default instance of OrderComparator.

Constructor Summary

Constructors

Constructor and Description
OrderComparator()

Method Summary

Modifier and Type	Method and Description
int	compare(Object o1, Object o2)
protected int	getOrder(Object obj) Determine the order value for the given object.
static void	sort(List<?> list) Sort the given List with a default OrderComparator.
static void	sort(Object[] array) Sort the given array with a default OrderComparator.
static void	sortIfNecessary(Object value) Sort the given array or List with a default OrderComparator, if necessary.

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

comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Field Detail

INSTANCE

public static final OrderComparator INSTANCE

Shared default instance of OrderComparator.

Constructor Detail

OrderComparator

public OrderComparator()

Method Detail

compare

public int compare(Object o1,
                   Object o2)

Specified by:

compare in interface Comparator<Object>

getOrder

protected int getOrder(Object obj)

Determine the order value for the given object.

The default implementation checks against the Ordered interface. Can be overridden in subclasses.

Parameters:

obj - the object to check

Returns:

the order value, or Ordered.LOWEST_PRECEDENCE as fallback

sort

public static void sort(List<?> list)

Sort the given List with a default OrderComparator.

Optimized to skip sorting for lists with size 0 or 1, in order to avoid unnecessary array extraction.

Parameters:

list - the List to sort

See Also:

Collections.sort(java.util.List, java.util.Comparator)

sort

public static void sort(Object[] array)

Sort the given array with a default OrderComparator.

Optimized to skip sorting for lists with size 0 or 1, in order to avoid unnecessary array extraction.

Parameters:

array - the array to sort

See Also:

Arrays.sort(Object[], java.util.Comparator)

sortIfNecessary

public static void sortIfNecessary(Object value)

Sort the given array or List with a default OrderComparator, if necessary. Simply skips sorting when given any other value.

Optimized to skip sorting for lists with size 0 or 1, in order to avoid unnecessary array extraction.

Parameters:

value - the array or List to sort

See Also:

Arrays.sort(Object[], java.util.Comparator)