public class NullComparator<E> extends Object implements Comparator<E>, Serializable
| Constructor and Description |
|---|
NullComparator()
Construct an instance that sorts
null higher than any
non-null object it is compared with. |
NullComparator(boolean nullsAreHigh)
Construct an instance that sorts
null higher or lower than
any non-null object it is compared with. |
NullComparator(Comparator<? super E> nonNullComparator)
Construct an instance that sorts
null higher than any
non-null object it is compared with. |
NullComparator(Comparator<? super E> nonNullComparator,
boolean nullsAreHigh)
Construct an instance that sorts
null higher or lower than
any non-null object it is compared with. |
| Modifier and Type | Method and Description |
|---|---|
int |
compare(E o1,
E o2)
Perform a comparison between two objects.
|
boolean |
equals(Object obj)
Determines whether the specified object represents a comparator that is
equal to this comparator.
|
int |
hashCode()
Implement a hash code for this comparator that is consistent with
equals(Object). |
public NullComparator()
null higher than any
non-null object it is compared with. When comparing two
non-null objects, the ComparableComparator is
used.public NullComparator(Comparator<? super E> nonNullComparator)
null higher than any
non-null object it is compared with. When comparing two
non-null objects, the specified Comparator is
used.nonNullComparator - the comparator to use when comparing two
non-null objects. This argument cannot be
nullNullPointerException - if nonNullComparator is
nullpublic NullComparator(boolean nullsAreHigh)
null higher or lower than
any non-null object it is compared with. When comparing
two non-null objects, the ComparableComparator is
used.nullsAreHigh - a true value indicates that
null should be compared as higher than a
non-null object. A false value indicates
that null should be compared as lower than a
non-null object.public NullComparator(Comparator<? super E> nonNullComparator, boolean nullsAreHigh)
null higher or lower than
any non-null object it is compared with. When comparing
two non-null objects, the specified Comparator is
used.nonNullComparator - the comparator to use when comparing two
non-null objects. This argument cannot be
nullnullsAreHigh - a true value indicates that
null should be compared as higher than a
non-null object. A false value indicates
that null should be compared as lower than a
non-null object.NullPointerException - if nonNullComparator is
nullpublic int compare(E o1, E o2)
null, a 0 value is returned. If one object
is null and the other is not, the result is determined on
whether the Comparator was constructed to have nulls as higher or lower
than other objects. If neither object is null, an
underlying comparator specified in the constructor (or the default) is
used to compare the non-null objects.compare in interface Comparator<E>o1 - the first object to compareo2 - the object to compare it to.-1 if o1 is "lower" than (less than,
before, etc.) o2; 1 if o1 is
"higher" than (greater than, after, etc.) o2; or
0 if o1 and o2 are equal.public int hashCode()
equals(Object).public boolean equals(Object obj)
equals in interface Comparator<E>equals in class Objectobj - the object to compare this comparator with.true if the specified object is a NullComparator
with equivalent null comparison behavior
(i.e. null high or low) and with equivalent underlying
non-null object comparators.Copyright © 2001–2013 The Apache Software Foundation. All rights reserved.