org.springframework.util.comparator

Class InstanceComparator<T>

java.lang.Object

org.springframework.util.comparator.InstanceComparator<T>

Type Parameters:

T - the type of objects being compared

All Implemented Interfaces:

java.util.Comparator<T>

public class InstanceComparator<T>
extends java.lang.Object
implements java.util.Comparator<T>

Compares objects based on an arbitrary class order. Allows objects to be sorted based on the types of class that they inherit, for example: this comparator can be used to sort a list Numbers such that Longs occur before Integers.

Only the specified instanceOrder classes are considered during comparison. If two objects are both instances of the ordered type this comparator will return a 0. Consider combining with a CompoundComparator if additional sorting is required.

Since:

3.2

Author:

Phillip Webb

See Also:

CompoundComparator

Field Summary

Fields

Modifier and Type	Field and Description
private java.lang.Class<?>[]	instanceOrder

Constructor Summary

Constructors

Constructor and Description
InstanceComparator(java.lang.Class<?>... instanceOrder) Create a new InstanceComparator instance.

Method Summary

Modifier and Type	Method and Description
int	compare(T o1, T o2)
private int	getOrder(T object)

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

instanceOrder

private final java.lang.Class<?>[] instanceOrder

Constructor Detail

InstanceComparator

public InstanceComparator(java.lang.Class<?>... instanceOrder)

Create a new InstanceComparator instance.

Parameters:

instanceOrder - the ordered list of classes that should be used when comparing objects. Classes earlier in the list will be be given a higher priority.

Method Detail

compare

public int compare(T o1,
                   T o2)

Specified by:

compare in interface java.util.Comparator<T>

getOrder

private int getOrder(T object)