Spec-Zone .ru
спецификации, руководства, описания, API
|
public abstract class Collator extends Object implements Comparator<Object>, Cloneable
Collator
class выполняет чувствительный к локали String
сравнение. Вы используете этот class, чтобы создать поиск и программы сортировки для текста естественного языка.
Collator
абстрактный class. Подклассы реализуют определенные стратегии сопоставления. Один подкласс, RuleBasedCollator
, в настоящий момент предоставляется Платформу Java и применим к широкому набору языков. Другие подклассы могут быть созданы, чтобы обработать более специализированные потребности.
Как другие чувствительные к локали классы, можно использовать статический метод фабрики, getInstance
, получить соответствующее Collator
объект для данной локали. Вы должны будете только смотреть на подклассы Collator
если Вы должны понять детали определенной стратегии сопоставления или если Вы должны изменить ту стратегию.
Следующий пример показывает, как сравнить две строки, используя Collator
для локали значения по умолчанию.
// Compare two strings in the default locale Collator myCollator = Collator.getInstance(); if( myCollator.compare("abc", "ABC") < 0 ) System.out.println("abc is less than ABC"); else System.out.println("abc is greater than or equal to ABC");
You can set a Collator
's strength property
to determine the level of difference considered significant in
comparisons. Four strengths are provided: PRIMARY
,
SECONDARY
, TERTIARY
, and IDENTICAL
.
The exact assignment of strengths to language features is
locale dependant. For example, in Czech, "e" and "f" are considered
primary differences, while "e" and "ě" are secondary differences,
"e" and "E" are tertiary differences and "e" and "e" are identical.
The following shows how both case and accents could be ignored for
US English.
//Get the Collator for US English and set its strength to PRIMARY Collator usCollator = Collator.getInstance(Locale.US); usCollator.setStrength(Collator.PRIMARY); if( usCollator.compare("abc", "ABC") == 0 ) { System.out.println("Strings are equivalent"); }
For comparing String
s exactly once, the compare
method provides the best performance. When sorting a list of
String
s however, it is generally necessary to compare each
String
multiple times. In this case, CollationKey
s
provide better performance. The CollationKey
class converts
a String
to a series of bits that can be compared bitwise
against other CollationKey
s. A CollationKey
is
created by a Collator
object for a given String
.
Note: CollationKey
s from different
Collator
s can not be compared. See the class description
for CollationKey
for an example using CollationKey
s.
RuleBasedCollator
,
CollationKey
,
CollationElementIterator
,
Locale
Modifier and Type | Field and Description |
---|---|
static int |
CANONICAL_DECOMPOSITION
Decomposition mode value.
|
static int |
FULL_DECOMPOSITION
Decomposition mode value.
|
static int |
ИДЕНТИЧНЫЙ
Collator strength value.
|
static int |
NO_DECOMPOSITION
Decomposition mode value.
|
static int |
ОСНОВНОЙ
Collator strength value.
|
static int |
ВТОРИЧНЫЙ
Collator strength value.
|
static int |
ТРЕТИЧНЫЙ
Collator strength value.
|
Modifier | Constructor and Description |
---|---|
protected |
Collator()
Default constructor.
|
Modifier and Type | Method and Description |
---|---|
Объект |
clone()
Overrides Cloneable
|
int |
compare(Object o1,
Object o2)
Compares its two arguments for order.
|
abstract int |
compare(String source,
String target)
Compares the source string to the target string according to the
collation rules for this Collator.
|
boolean |
equals(Object that)
Compares the equality of two Collators.
|
boolean |
equals(String source,
String target)
Convenience method for comparing the equality of two strings based on
this Collator's collation rules.
|
static Locale[] |
getAvailableLocales()
Returns an array of all locales for which the
getInstance methods of this class can return
localized instances. |
abstract CollationKey |
getCollationKey(String source)
Transforms the String into a series of bits that can be compared bitwise
to other CollationKeys.
|
int |
getDecomposition()
Get the decomposition mode of this Collator.
|
static Collator |
getInstance()
Gets the Collator for the current default locale.
|
static Collator |
getInstance(Locale desiredLocale)
Gets the Collator for the desired locale.
|
int |
getStrength()
Returns this Collator's strength property.
|
abstract int |
hashCode()
Generates the hash code for this Collator.
|
void |
setDecomposition(int decompositionMode)
Set the decomposition mode of this Collator.
|
void |
setStrength(int newStrength)
Sets this Collator's strength property.
|
finalize, getClass, notify, notifyAll, toString, wait, wait, wait
reverseOrder, thenComparing, thenComparing, thenComparing, thenComparing, thenComparing
public static final int PRIMARY
setStrength(int)
,
getStrength()
,
Constant Field Valuespublic static final int SECONDARY
setStrength(int)
,
getStrength()
,
Constant Field Valuespublic static final int TERTIARY
setStrength(int)
,
getStrength()
,
Constant Field Valuespublic static final int IDENTICAL
public static final int NO_DECOMPOSITION
public static final int CANONICAL_DECOMPOSITION
CANONICAL_DECOMPOSITION corresponds to Normalization Form D as
described in
public static final int FULL_DECOMPOSITION
FULL_DECOMPOSITION corresponds to Normalization Form KD as
described in
protected Collator()
getInstance()
public static Collator getInstance()
Locale.getDefault()
public static Collator getInstance(Locale desiredLocale)
desiredLocale
- the desired locale.Locale
,
ResourceBundle
public abstract int compare(String source, String target)
For a one time comparison, this method has the best performance. If a given String will be involved in multiple comparisons, CollationKey.compareTo has the best performance. See the Collator class description for an example using CollationKeys.
source
- the source string.target
- the target string.CollationKey
,
getCollationKey(java.lang.String)
public int compare(Object o1, Object o2)
This implementation merely returns
compare((String)o1, (String)o2)
.
compare
in interface Comparator<Object>
o1
- the first object to be compared.o2
- the second object to be compared.ClassCastException
- the arguments cannot be cast to Strings.Comparator
public abstract CollationKey getCollationKey(String source)
source
- the string to be transformed into a collation key.CollationKey
,
compare(java.lang.String, java.lang.String)
public boolean equals(String source, String target)
source
- the source string to be compared with.target
- the target string to be compared with.compare(java.lang.String, java.lang.String)
public int getStrength()
setStrength(int)
,
PRIMARY
,
SECONDARY
,
TERTIARY
,
IDENTICAL
public void setStrength(int newStrength)
newStrength
- the new strength value.IllegalArgumentException
- If the new strength value is not one of
PRIMARY, SECONDARY, TERTIARY or IDENTICAL.getStrength()
,
PRIMARY
,
SECONDARY
,
TERTIARY
,
IDENTICAL
public int getDecomposition()
The three values for decomposition mode are:
setDecomposition(int)
,
NO_DECOMPOSITION
,
CANONICAL_DECOMPOSITION
,
FULL_DECOMPOSITION
public void setDecomposition(int decompositionMode)
decompositionMode
- the new decomposition mode.IllegalArgumentException
- If the given value is not a valid decomposition
mode.getDecomposition()
,
NO_DECOMPOSITION
,
CANONICAL_DECOMPOSITION
,
FULL_DECOMPOSITION
public static Locale[] getAvailableLocales()
getInstance
methods of this class can return
localized instances.
The returned array represents the union of locales supported
by the Java runtime and by installed
CollatorProvider
implementations.
It must contain at least a Locale instance equal to
Locale.US
.Collator
instances are available.public Object clone()
public boolean equals(Object that)
equals
in interface Comparator<Object>
equals
in class Object
that
- the Collator to be compared with this.Object.hashCode()
,
HashMap
public abstract int hashCode()
hashCode
in class Object
Object.equals(java.lang.Object)
,
System.identityHashCode(java.lang.Object)
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2013, Oracle and/or its affiliates. All rights reserved.
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