net.sf.uadetector.internal.util
Class CompareNullSafe<T>

java.lang.Object
  net.sf.uadetector.internal.util.CompareNullSafe<T>

All Implemented Interfaces:

java.io.Serializable, java.util.Comparator<T>

Direct Known Subclasses:

BrowserOperatingSystemMappingComparator, IdentifiableComparator, OrderedPatternComparator

public abstract class CompareNullSafe<T>
extends java.lang.Object
implements java.util.Comparator<T>, java.io.Serializable

Compares two references to each other and null is assumed to be less than a non-null value. This class provides the first check for null safe comparison.

Author:

André Rouél

See Also:

Serialized Form

Constructor Summary

CompareNullSafe()

Method Summary

int	compare(T o1, T o2) Compares two objects null safe to each other.
static int	compareInt(int a, int b) Compares to integers.
abstract int	compareType(T o1, T o2)

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

equals

Constructor Detail

CompareNullSafe

public CompareNullSafe()

Method Detail

compareInt

public static int compareInt(int a,
                             int b)

Compares to integers.

Parameters:

a - first integer

b - second integer

Returns:

-1 if a is less, 0 if equal, or 1 if greater than b

compare

public int compare(T o1,
                   T o2)

Compares two objects null safe to each other.

Specified by:

compare in interface java.util.Comparator<T>

Parameters:

o1 - the first reference

o2 - the second reference

Returns:

a negative value if o1 < o2, zero if o1 = o2 and a positive value if o1 > o2

compareType

public abstract int compareType(T o1,
                                T o2)