Spring Framework 6.1.4 · org.springframework.util.comparator.InstanceComparator

public Class InstanceComparator<T>

extends Object
implements Comparator<T>

Class Inheritance

java.lang.Object
org.springframework.util.comparator.InstanceComparator

All Implemented Interfaces

java.util.Comparator

Type Parameters

<T>: the type of objects that may be compared by this comparator

Imports

java.util.Comparator, org.springframework.lang.Nullable, org.springframework.util.Assert

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 of 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 value of 0. Consider combining with Comparator#thenComparing(Comparator) if additional sorting is required.

Field Summary

Modifier and Type	Field and Description
private final Class<?>[]	instanceOrder

Constructor Summary

Access	Constructor and Description
public	InstanceComparator(Class<?>... the ordered list of classes that should be used when comparing objects. Classes earlier in the list will be given a higher priority. instanceOrder) Create a new `InstanceComparator` instance.

Method Summary

Modifier and Type	Method and Description
public int	compare(T the first object to be compared. o1, T the second object to be compared. o2) Implements java.util.Comparator.compare. Compares its two arguments for order.
private int	getOrder(T object)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

instanceOrder	back to summary
private final Class<?>[] instanceOrder

Constructor Detail

InstanceComparator back to summary

InstanceComparator	back to summary
public InstanceComparator(Class<?>... instanceOrder) Create a new `InstanceComparator` instance. Parameters instanceOrder:Class<?>[] the ordered list of classes that should be used when comparing objects. Classes earlier in the list will be given a higher priority.

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

Create a new InstanceComparator instance.

Parameters

instanceOrder:Class<?>[]: the ordered list of classes that should be used when comparing objects. Classes earlier in the list will be given a higher priority.

Method Detail

compare back to summary

compare	back to summary
public int compare(T o1, T o2) Implements java.util.Comparator.compare. Doc from java.util.Comparator.compare. Compares its two arguments for order. Returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second. The implementor must ensure that `signum(compare(x, y)) == -signum(compare(y, x))` for all `x` and `y`. (This implies that `compare(x, y)` must throw an exception if and only if `compare(y, x)` throws an exception.) The implementor must also ensure that the relation is transitive: `((compare(x, y)>0) && (compare(y, z)>0))` implies `compare(x, z)>0`. Finally, the implementor must ensure that `compare(x, y)==0` implies that `signum(compare(x, z))==signum(compare(y, z))` for all `z`. Parameters o1:T the first object to be compared. o2:T the second object to be compared. Returns:int a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second. Annotations @Override

public int compare(T o1, T o2)

Implements java.util.Comparator.compare.

Doc from java.util.Comparator.compare.

Compares its two arguments for order. Returns a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

The implementor must ensure that signum(compare(x, y)) == -signum(compare(y, x)) for all x and y. (This implies that compare(x, y) must throw an exception if and only if compare(y, x) throws an exception.)

The implementor must also ensure that the relation is transitive: ((compare(x, y)>0) && (compare(y, z)>0)) implies compare(x, z)>0.

Finally, the implementor must ensure that compare(x, y)==0 implies that signum(compare(x, z))==signum(compare(y, z)) for all z.

Parameters

o1:T: the first object to be compared.
o2:T: the second object to be compared.

Returns:int

a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.

Annotations

@Override

getOrder	back to summary
private int getOrder(T object)