Class CompareMode

java.lang.Object

org.h2.value.CompareMode

All Implemented Interfaces:

Comparator<Value>

Direct Known Subclasses:

CompareModeDefault, CompareModeIcu4J

public class CompareMode
extends Object
implements Comparator<Value>

Instances of this class can compare strings. Case sensitive and case insensitive comparison is supported, and comparison using a collator.

Field Summary

Fields

Modifier and Type	Field	Description
private static final boolean	CAN_USE_ICU4J
static final String	CHARSET	This constant means the charset specified should be used.
static final String	DEFAULT	This constant means the default collator should be used, even if ICU4J is in the classpath.
static final String	ICU4J	This constant means ICU4J should be used (this will fail if it is not in the classpath).
private static CompareMode	lastUsed
private static Locale[]	LOCALES
private final String	name
static final String	OFF	This constant means there is no collator set, and the default string comparison is to be used.
private final int	strength

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	CompareMode(String name, int strength)

Method Summary

Modifier and Type	Method	Description
int	compare(Value o1, Value o2)
(package private) static boolean	compareLocaleNames(Locale locale, String name)	Compare name of the locale with the given name.
int	compareString(String a, String b, boolean ignoreCase)	Compare two strings.
boolean	equals(Object obj)
boolean	equalsChars(String a, int ai, String b, int bi, boolean ignoreCase)	Compare two characters in a string.
static Locale[]	getCollationLocales(boolean onlyIfInitialized)	Returns available locales for collations.
static Collator	getCollator(String name)	Get the collator object for the given language name or language / country combination.
static CompareMode	getInstance(String name, int strength)	Create a new compare mode with the given collator and strength.
String	getName()
static String	getName(Locale l)	Get the collation name.
int	getStrength()
int	hashCode()

Methods inherited from class Object

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

Methods inherited from interface Comparator

reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Field Details

OFF

public static final String OFF

This constant means there is no collator set, and the default string comparison is to be used.

See Also:

• Constant Field Values

DEFAULT

public static final String DEFAULT

This constant means the default collator should be used, even if ICU4J is in the classpath.

See Also:

• Constant Field Values

ICU4J

public static final String ICU4J

This constant means ICU4J should be used (this will fail if it is not in the classpath).

See Also:

• Constant Field Values

CHARSET

public static final String CHARSET

This constant means the charset specified should be used. This will fail if the specified charset does not exist.

See Also:

• Constant Field Values

LOCALES

private static Locale[] LOCALES

lastUsed

private static volatile CompareMode lastUsed

CAN_USE_ICU4J

private static final boolean CAN_USE_ICU4J

name

private final String name

strength

private final int strength

Constructor Details

CompareMode

protected CompareMode(String name,
 int strength)

Method Details

getInstance

public static CompareMode getInstance(String name,
 int strength)

Create a new compare mode with the given collator and strength. If required, a new CompareMode is created, or if possible the last one is returned. A cache is used to speed up comparison when using a collator; CollationKey objects are cached.

Parameters:

name - the collation name or null

strength - the collation strength

Returns:

the compare mode

getCollationLocales

public static Locale[] getCollationLocales(boolean onlyIfInitialized)

Returns available locales for collations.

Parameters:

onlyIfInitialized - if true, returns null when locales are not yet initialized

Returns:

available locales for collations.

equalsChars

public boolean equalsChars(String a,
 int ai,
 String b,
 int bi,
 boolean ignoreCase)

Compare two characters in a string.

Parameters:

a - the first string

ai - the character index in the first string

b - the second string

bi - the character index in the second string

ignoreCase - true if a case-insensitive comparison should be made

Returns:

true if the characters are equals

compareString

public int compareString(String a,
 String b,
 boolean ignoreCase)

Compare two strings.

Parameters:

a - the first string

b - the second string

ignoreCase - true if a case-insensitive comparison should be made

Returns:

-1 if the first string is 'smaller', 1 if the second string is smaller, and 0 if they are equal

getName

public static String getName(Locale l)

Get the collation name.

Parameters:

l - the locale

Returns:

the name of the collation

compareLocaleNames

static boolean compareLocaleNames(Locale locale,
 String name)

Compare name of the locale with the given name. The case of the name is ignored.

Parameters:

locale - the locale

name - the name

Returns:

true if they match

getCollator

public static Collator getCollator(String name)

Get the collator object for the given language name or language / country combination.

Parameters:

name - the language name

Returns:

the collator

getName

public String getName()

getStrength

public int getStrength()

equals

public boolean equals(Object obj)

Specified by:

equals in interface Comparator<Value>

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

compare

public int compare(Value o1,
 Value o2)

Specified by:

compare in interface Comparator<Value>