com.atomicleopard.expressive

Class Expressive.Comparators

java.lang.Object

com.atomicleopard.expressive.Expressive.Comparators

Enclosing class:

Expressive

public static class Expressive.Comparators
extends Object

Provides common implementations of comparators.

To promote reusability and reduce code clutter, this class provides implementations of comparators that are commonly used in code.

Method Summary

Methods

Modifier and Type	Method and Description
static <T> Comparator<T>	all(Comparator<T>... comparators) Returns a comparator which compares using the given comparators.
static <T> Comparator<T>	all(Iterable<Comparator<T>> comparators) Returns a comparator which compares using the given comparators.
static <T extends Comparable<T>> Comparator<T>	as(Class<T> comparable) Returns a comparator for a given type that implements Comparable
static Comparator<String>	caseInsensitive() Returns a string comparator which ignores case.
static <T> ComparatorBuilder<T>	compare(Class<T> type) Returns a ComparatorBuilder which allows the creation of a comparator for the given type based on the values of bean properties on that object.
static <T> Comparator<T>	nullSafe(Comparator<T> delegate) Returns a comparator that can safely compare null values.
static <T> Comparator<T>	nullSafe(Comparator<T> delegate, boolean nullLast) Returns a comparator that can safely compare null values.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

compare

public static <T> ComparatorBuilder<T> compare(Class<T> type)

Returns a ComparatorBuilder which allows the creation of a comparator for the given type based on the values of bean properties on that object.

Parameters:

type - the type for which a comparator is being built

Returns:

a comparator builder which will allow a Comparator to be created

See Also:

ComparatorBuilder

nullSafe

public static <T> Comparator<T> nullSafe(Comparator<T> delegate)

Returns a comparator that can safely compare null values. Null values are considered to be 'greater than' non-null values.

Parameters:

delegate -

Returns:

a comparator which allows Comparator.compare(Object, Object) on null values

See Also:

nullSafe(Comparator, boolean)

nullSafe

public static <T> Comparator<T> nullSafe(Comparator<T> delegate,
                         boolean nullLast)

Returns a comparator that can safely compare null values. The second argument controls whether nulls are 'greater than' or 'less than' non-null values

Parameters:

delegate -

nullLast - if true, null values are considered 'greater than' non-null, if false null values are 'less than'

Returns:

a comparator which allows Comparator.compare(Object, Object) on null values

caseInsensitive

public static Comparator<String> caseInsensitive()

Returns a string comparator which ignores case.

Returns:

as

public static <T extends Comparable<T>> Comparator<T> as(Class<T> comparable)

Returns a comparator for a given type that implements Comparable

Parameters:

comparable - the type of the Comparable class

Returns:

a comparator for comparing comparable instances of the given type

all

public static <T> Comparator<T> all(Comparator<T>... comparators)

Returns a comparator which compares using the given comparators. The comparison occurs using the given comparators in order, and continues until a non-zero value is returned, or all comparators have been evaluated.

Parameters:

comparators -

Returns:

a comparator which compares using the given ordered comparators

all

public static <T> Comparator<T> all(Iterable<Comparator<T>> comparators)

Returns a comparator which compares using the given comparators. The comparison occurs using the given comparators in order, and continues until a non-zero value is returned, or all comparators have been evaluated.

Parameters:

comparators -

Returns:

a comparator which compares using the given ordered comparators