com.helger.commons.compare

Class AbstractComparator<DATATYPE>

java.lang.Object

com.helger.commons.compare.AbstractComparator<DATATYPE>

Type Parameters:

DATATYPE - The data type to be compared

All Implemented Interfaces:

Serializable, Comparator<DATATYPE>

Direct Known Subclasses:

AbstractCollationComparator, AbstractIntegerComparator, AbstractNumericComparator, AbstractPartComparator, AbstractPartComparatorComparable, ComparatorChangeLogEntryDate, ComparatorComparable, ComparatorComparableNullAware, ComparatorMimeTypeInfoPrimaryMimeType, ComparatorQName, ComparatorStringLongestFirst

public abstract class AbstractComparator<DATATYPE>
extends Object
implements Comparator<DATATYPE>, Serializable

Abstract comparator class that supports a sort order. This comparator may only be applied on non-null values.

Author:

Philip Helger

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
AbstractComparator() Comparator with default sort order and no nested comparator.
AbstractComparator(Comparator<? super DATATYPE> aNestedComparator) Comparator with default sort order and a nested comparator.
AbstractComparator(ESortOrder eSortOrder) Constructor with sort order.
AbstractComparator(ESortOrder eSortOrder, Comparator<? super DATATYPE> aNestedComparator) Comparator with sort order and a nested comparator.

Method Summary

Modifier and Type	Method and Description
int	compare(DATATYPE aElement1, DATATYPE aElement2)
Comparator<? super DATATYPE>	getNestedComparator()
ESortOrder	getSortOrder()
protected abstract int	mainCompare(DATATYPE aElement1, DATATYPE aElement2)
AbstractComparator<DATATYPE>	setSortOrder(ESortOrder eSortOrder) Call this to enable sorting after the constructor was invoked.

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

AbstractComparator

public AbstractComparator()

Comparator with default sort order and no nested comparator.

AbstractComparator

public AbstractComparator(@Nonnull
                          ESortOrder eSortOrder)

Constructor with sort order.

Parameters:

eSortOrder - The sort order to use. May not be null.

AbstractComparator

public AbstractComparator(@Nullable
                          Comparator<? super DATATYPE> aNestedComparator)

Comparator with default sort order and a nested comparator.

Parameters:

aNestedComparator - The nested comparator to be invoked, when the main comparison resulted in 0.

AbstractComparator

public AbstractComparator(@Nonnull
                          ESortOrder eSortOrder,
                          @Nullable
                          Comparator<? super DATATYPE> aNestedComparator)

Comparator with sort order and a nested comparator.

Parameters:

eSortOrder - The sort order to use. May not be null.

aNestedComparator - The nested comparator to be invoked, when the main comparison resulted in 0.

Method Detail

getSortOrder

@Nonnull
public final ESortOrder getSortOrder()

Returns:

The currently assigned sort order. Never null.

setSortOrder

@Nonnull
public final AbstractComparator<DATATYPE> setSortOrder(@Nonnull
                                                                 ESortOrder eSortOrder)

Call this to enable sorting after the constructor was invoked.

Parameters:

eSortOrder - The sort order to use. May not be null.

Returns:

this

getNestedComparator

@Nonnull
public final Comparator<? super DATATYPE> getNestedComparator()

Returns:

The nested comparator. May be null.

mainCompare

protected abstract int mainCompare(DATATYPE aElement1,
                                   DATATYPE aElement2)

Parameters:

aElement1 - First element to compare. No information on the null status.

aElement2 - Second element to compare. No information on the null status.

Returns:

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

compare

public final int compare(DATATYPE aElement1,
                         DATATYPE aElement2)

Specified by:

compare in interface Comparator<DATATYPE>