de.alpharogroup.comparators

Class NullCheckComparator<T>

java.lang.Object

de.alpharogroup.comparators.NullCheckComparator<T>

Type Parameters:

T - the generic type of the Comparator object that will be decorated

All Implemented Interfaces:

Serializable, Comparator<T>

public class NullCheckComparator<T>
extends Object
implements Comparator<T>, Serializable

The class NullCheckComparator decorates another Comparator object to compare null and non-null values. Before the decorated Comparator will be executed null check will be executed. Over the flag 'nullIsGreaterThan' can be controlled whether null object values are greater or less than non-null object values.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
NullCheckComparator(Comparator<T> decoratedComparator) Instantiates a NullCheckComparator from the given Comparator object.
NullCheckComparator(Comparator<T> decoratedComparator, boolean nullIsGreaterThan) Instantiates a NullCheckComparator from the given Comparator object and the given flag.

Method Summary

Modifier and Type	Method and Description
int	compare(T object, T compareWithObject)
static <T> Comparator<T>	of(Comparator<T> decoratedComparator) Factory method to create a new NullCheckComparator object from the given Comparator object.
static <T> NullCheckComparator<T>	of(Comparator<T> decoratedComparator, boolean nullIsGreaterThan) Factory method to create a new NullCheckComparator object from the given Comparator 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

Constructor Detail

NullCheckComparator

public NullCheckComparator(Comparator<T> decoratedComparator)

Instantiates a NullCheckComparator from the given Comparator object. The flag nullIsGreaterThan is set to false so null objects are smaller then non null objects.

Parameters:

decoratedComparator - the Comparator object that will be decorated

NullCheckComparator

public NullCheckComparator(Comparator<T> decoratedComparator,
                           boolean nullIsGreaterThan)

Instantiates a NullCheckComparator from the given Comparator object and the given flag.

Parameters:

decoratedComparator - the Comparator object that will be decorated

nullIsGreaterThan - the flag that specifies if null objects is greater than non null objects.

Method Detail

of

public static <T> Comparator<T> of(Comparator<T> decoratedComparator)

Factory method to create a new NullCheckComparator object from the given Comparator object.

Type Parameters:

T - the generic type of the Comparator object that will be decorated

Parameters:

decoratedComparator - the Comparator object that will be decorated

Returns:

the new decorated Comparator object

of

public static <T> NullCheckComparator<T> of(Comparator<T> decoratedComparator,
                                            boolean nullIsGreaterThan)

Factory method to create a new NullCheckComparator object from the given Comparator object.

Type Parameters:

T - the generic type of the Comparator object that will be decorated

Parameters:

decoratedComparator - the Comparator object that will be decorated

nullIsGreaterThan - the flag that specifies if null objects is greater than non null objects.

Returns:

the new NullCheckComparator object

compare

public int compare(T object,
                   T compareWithObject)

Specified by:

compare in interface Comparator<T>