Package org.apache.commons.collections.comparators

Class NullComparator

java.lang.Object
org.apache.commons.collections.comparators.NullComparator
All Implemented Interfaces:
Serializable, Comparator
@Deprecated(since="2021-04-30") public class NullComparator extends Object implements Comparator, Serializable
Deprecated.
Apache Commons Collections version 3.x is being deprecated from AEMaaCS. The upgraded version 4.4 of Commons Collections is already included as replacement. Customers are advised to upgrade to this version of the library. Please note: the package name was changed to org.apache.commons.collections4. Further note that there are AEM APIs currently exposing the old collections classes; these will be updated in upcoming releases.
A Comparator that will compare nulls to be either lower or higher than other objects.
Since:
Commons Collections 2.0
See Also:

  • Constructor Details

    • NullComparator

      public NullComparator()
      Deprecated.
      Construct an instance that sorts null higher than any non-null object it is compared with. When comparing two non-null objects, the ComparableComparator is used.

    • NullComparator

      public NullComparator(Comparator nonNullComparator)
      Deprecated.
      Construct an instance that sorts null higher than any non-null object it is compared with. When comparing two non-null objects, the specified Comparator is used.
      Parameters:
      nonNullComparator - the comparator to use when comparing two non-null objects. This argument cannot be null
      Throws:
      NullPointerException - if nonNullComparator is null

    • NullComparator

      public NullComparator(boolean nullsAreHigh)
      Deprecated.
      Construct an instance that sorts null higher or lower than any non-null object it is compared with. When comparing two non-null objects, the ComparableComparator is used.
      Parameters:
      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.

    • NullComparator

      public NullComparator(Comparator nonNullComparator, boolean nullsAreHigh)
      Deprecated.
      Construct an instance that sorts null higher or lower than any non-null object it is compared with. When comparing two non-null objects, the specified Comparator is used.
      Parameters:
      nonNullComparator - the comparator to use when comparing two non-null objects. This argument cannot be null
      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.
      Throws:
      NullPointerException - if nonNullComparator is null

  • Method Details

    • compare

      public int compare(Object o1, Object o2)
      Deprecated.
      Perform a comparison between two objects. If both objects are 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.
      Specified by:
      compare in interface Comparator
      Parameters:
      o1 - the first object to compare
      o2 - the object to compare it to.
      Returns:
      -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.

    • hashCode

      public int hashCode()
      Deprecated.
      Implement a hash code for this comparator that is consistent with equals(Object).
      Overrides:
      hashCode in class Object
      Returns:
      a hash code for this comparator.

    • equals

      public boolean equals(Object obj)
      Deprecated.
      Determines whether the specified object represents a comparator that is equal to this comparator.
      Specified by:
      equals in interface Comparator
      Overrides:
      equals in class Object
      Parameters:
      obj - the object to compare this comparator with.
      Returns:
      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.