org.springframework.util.comparator

类 NullSafeComparator<T>

java.lang.Object

org.springframework.util.comparator.NullSafeComparator<T>

所有已实现的接口:

Comparator<T>

public class NullSafeComparator<T>
extends Object
implements Comparator<T>

A Comparator that will safely compare nulls to be lower or higher than other objects. Can decorate a given Comparator or work on Comparables.

从以下版本开始:

1.2.2

作者:

Keith Donald, Juergen Hoeller

另请参阅:

Comparable

字段概要

字段

限定符和类型	字段和说明
static NullSafeComparator	NULLS_HIGH A shared default instance of this comparator, treating nulls higher than non-null objects.
static NullSafeComparator	NULLS_LOW A shared default instance of this comparator, treating nulls lower than non-null objects.

构造器概要

构造器

构造器和说明
NullSafeComparator(Comparator<T> comparator, boolean nullsLow) Create a NullSafeComparator that sorts null based on the provided flag, decorating the given Comparator.

方法概要

限定符和类型	方法和说明
int	compare(T o1, T o2)
boolean	equals(Object other)
int	hashCode()
String	toString()

从类继承的方法 java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

从接口继承的方法 java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

字段详细资料

NULLS_LOW

public static final NullSafeComparator NULLS_LOW

A shared default instance of this comparator, treating nulls lower than non-null objects.

另请参阅:

Comparators.nullsLow()

NULLS_HIGH

public static final NullSafeComparator NULLS_HIGH

A shared default instance of this comparator, treating nulls higher than non-null objects.

另请参阅:

Comparators.nullsHigh()

构造器详细资料

NullSafeComparator

public NullSafeComparator(Comparator<T> comparator,
                          boolean nullsLow)

Create a NullSafeComparator that sorts null based on the provided flag, decorating the given Comparator.

When comparing two non-null objects, the specified Comparator will be used. The given underlying Comparator must be able to handle the elements that this Comparator will be applied to.

参数:

comparator - the comparator to use when comparing two non-null objects

nullsLow - whether to treat nulls lower or higher than non-null objects

方法详细资料

compare

public int compare(@Nullable
                   T o1,
                   @Nullable
                   T o2)

指定者:

compare 在接口中 Comparator<T>

equals

public boolean equals(Object other)

指定者:

equals 在接口中 Comparator<T>

覆盖:

equals 在类中 Object

hashCode

public int hashCode()

覆盖:

hashCode 在类中 Object

toString

public String toString()

覆盖:

toString 在类中 Object