Class ComparatorUtils


  • @Deprecated(since="2021-04-30")
    public class ComparatorUtils
    extends java.lang.Object
    Deprecated.
    Commons Collections 3 is in maintenance mode. Commons Collections 4 should be used instead.
    Provides convenient static utility methods for Comparator objects.

    Most of the functionality in this class can also be found in the comparators package. This class merely provides a convenient central place if you have use for more than one class in the comparators subpackage.

    Since:
    Commons Collections 2.1
    • Field Summary

      Fields 
      Modifier and Type Field Description
      static java.util.Comparator NATURAL_COMPARATOR
      Deprecated.
      Comparator for natural sort order.
    • Constructor Summary

      Constructors 
      Constructor Description
      ComparatorUtils()
      Deprecated.
      ComparatorUtils should not normally be instantiated.
    • Method Summary

      All Methods Static Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      static java.util.Comparator booleanComparator​(boolean trueFirst)
      Deprecated.
      Gets a Comparator that can sort Boolean objects.
      static java.util.Comparator chainedComparator​(java.util.Collection comparators)
      Deprecated.
      Gets a comparator that compares using a collection of Comparators, applied in (default iterator) sequence until one returns not equal or the collection is exhausted.
      static java.util.Comparator chainedComparator​(java.util.Comparator[] comparators)
      Deprecated.
      Gets a comparator that compares using an array of Comparators, applied in sequence until one returns not equal or the array is exhausted.
      static java.util.Comparator chainedComparator​(java.util.Comparator comparator1, java.util.Comparator comparator2)
      Deprecated.
      Gets a comparator that compares using two Comparators.
      static java.lang.Object max​(java.lang.Object o1, java.lang.Object o2, java.util.Comparator comparator)
      Deprecated.
      Returns the larger of the given objects according to the given comparator, returning the second object if the comparator returns equal.
      static java.lang.Object min​(java.lang.Object o1, java.lang.Object o2, java.util.Comparator comparator)
      Deprecated.
      Returns the smaller of the given objects according to the given comparator, returning the second object if the comparator returns equal.
      static java.util.Comparator naturalComparator()
      Deprecated.
      Gets a comparator that uses the natural order of the objects.
      static java.util.Comparator nullHighComparator​(java.util.Comparator comparator)
      Deprecated.
      Gets a Comparator that controls the comparison of null values.
      static java.util.Comparator nullLowComparator​(java.util.Comparator comparator)
      Deprecated.
      Gets a Comparator that controls the comparison of null values.
      static java.util.Comparator reversedComparator​(java.util.Comparator comparator)
      Deprecated.
      Gets a comparator that reverses the order of the given comparator.
      static java.util.Comparator transformedComparator​(java.util.Comparator comparator, Transformer transformer)
      Deprecated.
      Gets a Comparator that passes transformed objects to the given comparator.
      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • NATURAL_COMPARATOR

        public static final java.util.Comparator NATURAL_COMPARATOR
        Deprecated.
        Comparator for natural sort order.
        See Also:
        ComparableComparator.getInstance()
    • Constructor Detail

      • ComparatorUtils

        public ComparatorUtils()
        Deprecated.
        ComparatorUtils should not normally be instantiated.
    • Method Detail

      • naturalComparator

        public static java.util.Comparator naturalComparator()
        Deprecated.
        Gets a comparator that uses the natural order of the objects.
        Returns:
        a comparator which uses natural order
      • chainedComparator

        public static java.util.Comparator chainedComparator​(java.util.Comparator comparator1,
                                                             java.util.Comparator comparator2)
        Deprecated.
        Gets a comparator that compares using two Comparators.

        The second comparator is used if the first comparator returns equal.

        Parameters:
        comparator1 - the first comparator to use, not null
        comparator2 - the first comparator to use, not null
        Returns:
        a ComparatorChain formed from the two comparators
        Throws:
        java.lang.NullPointerException - if either comparator is null
        See Also:
        ComparatorChain
      • chainedComparator

        public static java.util.Comparator chainedComparator​(java.util.Comparator[] comparators)
        Deprecated.
        Gets a comparator that compares using an array of Comparators, applied in sequence until one returns not equal or the array is exhausted.
        Parameters:
        comparators - the comparators to use, not null or empty or containing nulls
        Returns:
        a ComparatorChain formed from the input comparators
        Throws:
        java.lang.NullPointerException - if comparators array is null or contains a null
        See Also:
        ComparatorChain
      • chainedComparator

        public static java.util.Comparator chainedComparator​(java.util.Collection comparators)
        Deprecated.
        Gets a comparator that compares using a collection of Comparators, applied in (default iterator) sequence until one returns not equal or the collection is exhausted.
        Parameters:
        comparators - the comparators to use, not null or empty or containing nulls
        Returns:
        a ComparatorChain formed from the input comparators
        Throws:
        java.lang.NullPointerException - if comparators collection is null or contains a null
        java.lang.ClassCastException - if the comparators collection contains the wrong object type
        See Also:
        ComparatorChain
      • reversedComparator

        public static java.util.Comparator reversedComparator​(java.util.Comparator comparator)
        Deprecated.
        Gets a comparator that reverses the order of the given comparator.
        Parameters:
        comparator - the comparator to reverse
        Returns:
        a comparator that reverses the order of the input comparator
        See Also:
        ReverseComparator
      • booleanComparator

        public static java.util.Comparator booleanComparator​(boolean trueFirst)
        Deprecated.
        Gets a Comparator that can sort Boolean objects.

        The parameter specifies whether true or false is sorted first.

        The comparator throws NullPointerException if a null value is compared.

        Parameters:
        trueFirst - when true, sort true Booleans before false Booleans.
        Returns:
        a comparator that sorts booleans
      • nullLowComparator

        public static java.util.Comparator nullLowComparator​(java.util.Comparator comparator)
        Deprecated.
        Gets a Comparator that controls the comparison of null values.

        The returned comparator will consider a null value to be less than any nonnull value, and equal to any other null value. Two nonnull values will be evaluated with the given comparator.

        Parameters:
        comparator - the comparator that wants to allow nulls
        Returns:
        a version of that comparator that allows nulls
        See Also:
        NullComparator
      • nullHighComparator

        public static java.util.Comparator nullHighComparator​(java.util.Comparator comparator)
        Deprecated.
        Gets a Comparator that controls the comparison of null values.

        The returned comparator will consider a null value to be greater than any nonnull value, and equal to any other null value. Two nonnull values will be evaluated with the given comparator.

        Parameters:
        comparator - the comparator that wants to allow nulls
        Returns:
        a version of that comparator that allows nulls
        See Also:
        NullComparator
      • transformedComparator

        public static java.util.Comparator transformedComparator​(java.util.Comparator comparator,
                                                                 Transformer transformer)
        Deprecated.
        Gets a Comparator that passes transformed objects to the given comparator.

        Objects passed to the returned comparator will first be transformed by the given transformer before they are compared by the given comparator.

        Parameters:
        comparator - the sort order to use
        transformer - the transformer to use
        Returns:
        a comparator that transforms its input objects before comparing them
        See Also:
        TransformingComparator
      • min

        public static java.lang.Object min​(java.lang.Object o1,
                                           java.lang.Object o2,
                                           java.util.Comparator comparator)
        Deprecated.
        Returns the smaller of the given objects according to the given comparator, returning the second object if the comparator returns equal.
        Parameters:
        o1 - the first object to compare
        o2 - the second object to compare
        comparator - the sort order to use
        Returns:
        the smaller of the two objects
      • max

        public static java.lang.Object max​(java.lang.Object o1,
                                           java.lang.Object o2,
                                           java.util.Comparator comparator)
        Deprecated.
        Returns the larger of the given objects according to the given comparator, returning the second object if the comparator returns equal.
        Parameters:
        o1 - the first object to compare
        o2 - the second object to compare
        comparator - the sort order to use
        Returns:
        the larger of the two objects