com.phloc.commons.compare

Class CompareUtils

java.lang.Object

com.phloc.commons.compare.CompareUtils

@Immutable
public final class CompareUtils
extends Object

A small helper class that provides comparison methods that are null safe. Also provides secure ways to compare double and float values.

Author:

Philip Helger

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	DEFAULT_NULL_VALUES_COME_FIRST By default null values come first

Method Summary

Methods

Modifier and Type	Method and Description
static int	compare(byte n1, byte n2) Special version for byte
static int	compare(char n1, char n2) Special version for byte
static int	compare(double d1, double d2) Special version for doubles
static int	compare(float f1, float f2) Special version for floats
static int	compare(int n1, int n2) Special version for int
static int	compare(long n1, long n2) Special version for long
static int	compare(short n1, short n2) Special version for short
static int	compareFalseBeforeTrue(boolean b1, boolean b2) Special version for boolean, true before false
static int	compareTrueBeforeFalse(boolean b1, boolean b2) Special version for boolean, true before false
static <DATATYPE extends Comparable<? super DATATYPE>> int	nullSafeCompare(DATATYPE aObj1, DATATYPE aObj2) Compare the passed items and handle null values correctly.
static <DATATYPE extends Comparable<? super DATATYPE>> int	nullSafeCompare(DATATYPE aObj1, DATATYPE aObj2, boolean bNullValuesComeFirst) Compare the passed items and handle null values correctly.
static <DATATYPE> int	nullSafeCompare(DATATYPE aObj1, DATATYPE aObj2, Comparator<DATATYPE> aComp) Compare the passed items and handle null values correctly.
static <DATATYPE> int	nullSafeCompare(DATATYPE aObj1, DATATYPE aObj2, Comparator<DATATYPE> aComp, boolean bNullValuesComeFirst) Compare the passed items and handle null values correctly.
static int	nullSafeCompare(String sStr1, String sStr2, Collator aCollator)
static int	nullSafeCompare(String sStr1, String sStr2, Collator aCollator, boolean bNullValuesComeFirst)
static int	nullSafeCompare(String sStr1, String sStr2, Locale aSortLocale)
static int	nullSafeCompare(String sStr1, String sStr2, Locale aSortLocale, boolean bNullValuesComeFirst)

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_NULL_VALUES_COME_FIRST

public static final boolean DEFAULT_NULL_VALUES_COME_FIRST

By default null values come first

See Also:

Constant Field Values

Method Detail

compareTrueBeforeFalse

public static int compareTrueBeforeFalse(boolean b1,
                         boolean b2)

Special version for boolean, true before false

Parameters:

b1 - First value

b2 - Second value

Returns:

-1, 0 or + 1

compareFalseBeforeTrue

public static int compareFalseBeforeTrue(boolean b1,
                         boolean b2)

Special version for boolean, true before false

Parameters:

b1 - First value

b2 - Second value

Returns:

-1, 0 or + 1

compare

public static int compare(byte n1,
          byte n2)

Special version for byte

Parameters:

n1 - First value

n2 - Second value

Returns:

-1, 0 or + 1

compare

public static int compare(char n1,
          char n2)

Special version for byte

Parameters:

n1 - First value

n2 - Second value

Returns:

-1, 0 or + 1

compare

public static int compare(double d1,
          double d2)

Special version for doubles

Parameters:

d1 - First value

d2 - Second value

Returns:

-1, 0 or + 1

compare

public static int compare(float f1,
          float f2)

Special version for floats

Parameters:

f1 - First value

f2 - Second value

Returns:

-1, 0 or + 1

compare

public static int compare(int n1,
          int n2)

Special version for int

Parameters:

n1 - First value

n2 - Second value

Returns:

-1, 0 or + 1

compare

public static int compare(long n1,
          long n2)

Special version for long

Parameters:

n1 - First value

n2 - Second value

Returns:

-1, 0 or + 1

compare

public static int compare(short n1,
          short n2)

Special version for short

Parameters:

n1 - First value

n2 - Second value

Returns:

-1, 0 or + 1

nullSafeCompare

public static <DATATYPE extends Comparable<? super DATATYPE>> int nullSafeCompare(@Nullable
                                                                  DATATYPE aObj1,
                                                                  @Nullable
                                                                  DATATYPE aObj2)

Compare the passed items and handle null values correctly. A null value is always smaller than a non-null value.

Type Parameters:

DATATYPE - Any comparable object to be used. Both need to be of the same type.

Parameters:

aObj1 - First object to compare. May be null.

aObj2 - Second object to compare. May be null.

Returns:

0 if they are equal (or both null), -1 or +1.

nullSafeCompare

public static <DATATYPE extends Comparable<? super DATATYPE>> int nullSafeCompare(@Nullable
                                                                  DATATYPE aObj1,
                                                                  @Nullable
                                                                  DATATYPE aObj2,
                                                                  boolean bNullValuesComeFirst)

Compare the passed items and handle null values correctly. A null value is always smaller than a non-null value.

Type Parameters:

DATATYPE - Any comparable object to be used. Both need to be of the same type.

Parameters:

aObj1 - First object to compare. May be null.

aObj2 - Second object to compare. May be null.

bNullValuesComeFirst - if true null values are ordered before non-null values

Returns:

0 if they are equal (or both null), -1 or +1.

nullSafeCompare

public static <DATATYPE> int nullSafeCompare(@Nullable
                             DATATYPE aObj1,
                             @Nullable
                             DATATYPE aObj2,
                             @Nonnull
                             Comparator<DATATYPE> aComp)

Compare the passed items and handle null values correctly. A null value is always smaller than a non-null value.

Type Parameters:

DATATYPE - Any object to be used. Both need to be of the same type.

Parameters:

aObj1 - First object to compare. May be null.

aObj2 - Second object to compare. May be null.

aComp - The comparator to be used if both parameters are not null. The comparator itself may not be null.

Returns:

0 if they are equal (or both null), -1 or +1.

nullSafeCompare

public static <DATATYPE> int nullSafeCompare(@Nullable
                             DATATYPE aObj1,
                             @Nullable
                             DATATYPE aObj2,
                             @Nonnull
                             Comparator<DATATYPE> aComp,
                             boolean bNullValuesComeFirst)

Compare the passed items and handle null values correctly. A null value is always smaller than a non-null value.

Type Parameters:

DATATYPE - Any object to be used. Both need to be of the same type.

Parameters:

aObj1 - First object to compare. May be null.

aObj2 - Second object to compare. May be null.

aComp - The comparator to be used if both parameters are not null. The comparator itself may not be null.

bNullValuesComeFirst - if true null values are ordered before non-null values

Returns:

0 if they are equal (or both null), -1 or +1.

nullSafeCompare

public static int nullSafeCompare(@Nullable
                  String sStr1,
                  @Nullable
                  String sStr2,
                  @Nonnull
                  Locale aSortLocale)

nullSafeCompare

public static int nullSafeCompare(@Nullable
                  String sStr1,
                  @Nullable
                  String sStr2,
                  @Nonnull
                  Locale aSortLocale,
                  boolean bNullValuesComeFirst)

nullSafeCompare

public static int nullSafeCompare(@Nullable
                  String sStr1,
                  @Nullable
                  String sStr2,
                  @Nonnull
                  Collator aCollator)

nullSafeCompare

public static int nullSafeCompare(@Nullable
                  String sStr1,
                  @Nullable
                  String sStr2,
                  @Nonnull
                  Collator aCollator,
                  boolean bNullValuesComeFirst)