org.apache.commons.collections
public class ComparatorUtils extends Object
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
Version: $Revision: 155406 $ $Date: 2005-02-26 12:55:26 +0000 (Sat, 26 Feb 2005) $
Field Summary | |
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static Comparator | NATURAL_COMPARATOR
Comparator for natural sort order.
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Constructor Summary | |
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ComparatorUtils()
ComparatorUtils should not normally be instantiated. |
Method Summary | |
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static Comparator | booleanComparator(boolean trueFirst)
Gets a Comparator that can sort Boolean objects.
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static Comparator | chainedComparator(Comparator comparator1, Comparator comparator2)
Gets a comparator that compares using two Comparators.
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static Comparator | chainedComparator(Comparator[] comparators)
Gets a comparator that compares using an array of Comparators, applied
in sequence until one returns not equal or the array is exhausted.
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static Comparator | chainedComparator(Collection comparators)
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.
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static Object | max(Object o1, Object o2, Comparator comparator)
Returns the larger of the given objects according to the given
comparator, returning the second object if the comparator
returns equal.
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static Object | min(Object o1, Object o2, Comparator comparator)
Returns the smaller of the given objects according to the given
comparator, returning the second object if the comparator
returns equal.
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static Comparator | naturalComparator()
Gets a comparator that uses the natural order of the objects.
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static Comparator | nullHighComparator(Comparator comparator)
Gets a Comparator that controls the comparison of null values.
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static Comparator | nullLowComparator(Comparator comparator)
Gets a Comparator that controls the comparison of null values.
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static Comparator | reversedComparator(Comparator comparator)
Gets a comparator that reverses the order of the given comparator.
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static Comparator | transformedComparator(Comparator comparator, Transformer transformer)
Gets a Comparator that passes transformed objects to the given comparator.
|
See Also: ComparableComparator
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
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: NullPointerException if either comparator is null
See Also: ComparatorChain
Parameters: comparators the comparators to use, not null or empty or containing nulls
Returns: a ComparatorChain formed from the input comparators
Throws: NullPointerException if comparators array is null or contains a null
See Also: ComparatorChain
Parameters: comparators the comparators to use, not null or empty or containing nulls
Returns: a ComparatorChain formed from the input comparators
Throws: NullPointerException if comparators collection is null or contains a null ClassCastException if the comparators collection contains the wrong object type
See Also: ComparatorChain
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
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
Returns: a comparator which uses natural order
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
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
Parameters: comparator the comparator to reverse
Returns: a comparator that reverses the order of the input comparator
See Also: ReverseComparator
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