/**
*******************************************************************************
* Copyright (C) 1996-2005, International Business Machines Corporation and *
* others. All Rights Reserved. *
*******************************************************************************
*
*
*******************************************************************************
*/
package com.ibm.icu4jni.text;
import java.util.Locale;
import com.ibm.icu4jni.text.RuleBasedCollator;
/**
* Abstract class handling locale specific collation via JNI and ICU.
* Subclasses implement specific collation strategies. One subclass,
* com.ibm.icu4jni.text.RuleBasedCollator, is currently provided and is
* applicable to a wide set of languages. Other subclasses may be created to
* handle more specialized needs.
* You can use the static factory method, getInstance(), to obtain the
* appropriate Collator object for a given locale.
*
* <pre>
* // 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");
* }
* </pre>
*
* You can set a Collator's strength property to determine the level of
* difference considered significant in comparisons.
* Five strengths in CollationAttribute are provided: VALUE_PRIMARY,
* VALUE_SECONDARY, VALUE_TERTIARY, VALUE_QUARTENARY and VALUE_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 "?" latin small letter e with circumflex are secondary differences,
* "e" and "E" are tertiary differences and "e" and "e" are identical.
*
* <p>
* The following shows how both case and accents could be ignored for US
* English.
* <pre>
* //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");
* }
* </pre>
* For comparing Strings exactly once, the compare method provides the best
* performance.
* When sorting a list of Strings however, it is generally necessary to compare
* each String multiple times.
* In this case, com.ibm.icu4jni.text.CollationKey provide better performance.
* The CollationKey class converts a String to a series of bits that can be
* compared bitwise against other CollationKeys.
* A CollationKey is created by a Collator object for a given String.
* Note: CollationKeys from different Collators can not be compared.
* </p>
*
* Considerations :
* 1) ErrorCode not returned to user throw exceptions instead
* 2) Similar API to java.text.Collator
* @author syn wee quek
* @stable ICU 2.4
*/
public abstract class Collator implements Cloneable
{
// public data members ---------------------------------------------------
/**
* Strongest collator strength value. Typically used to denote differences
* between base characters. See class documentation for more explanation.
* @see #setStrength
* @see #getStrength
* @stable ICU 2.4
*/
public final static int PRIMARY = CollationAttribute.VALUE_PRIMARY;
/**
* Second level collator strength value.
* Accents in the characters are considered secondary differences.
* Other differences between letters can also be considered secondary
* differences, depending on the language.
* See class documentation for more explanation.
* @see #setStrength
* @see #getStrength
* @stable ICU 2.4
*/
public final static int SECONDARY = CollationAttribute.VALUE_SECONDARY;
/**
* Third level collator strength value.
* Upper and lower case differences in characters are distinguished at this
* strength level. In addition, a variant of a letter differs from the base
* form on the tertiary level.
* See class documentation for more explanation.
* @see #setStrength
* @see #getStrength
* @stable ICU 2.4
*/
public final static int TERTIARY = CollationAttribute.VALUE_TERTIARY;
/**
* Fourth level collator strength value.
* When punctuation is ignored
* <a href="http://www-124.ibm.com/icu/userguide/Collate_Concepts.html#Ignoring_Punctuation">
* (see Ignoring Punctuations in the user guide)</a> at PRIMARY to TERTIARY
* strength, an additional strength level can
* be used to distinguish words with and without punctuation.
* See class documentation for more explanation.
* @see #setStrength
* @see #getStrength
* @stable ICU 2.4
*/
public final static int QUATERNARY = CollationAttribute.VALUE_QUATERNARY;
/**
* <p>
* Smallest Collator strength value. When all other strengths are equal,
* the IDENTICAL strength is used as a tiebreaker. The Unicode code point
* values of the NFD form of each string are compared, just in case there
* is no difference.
* See class documentation for more explanation.
* </p>
* <p>
* Note this value is different from JDK's
* </p>
* @stable ICU 2.4
*/
public final static int IDENTICAL = CollationAttribute.VALUE_IDENTICAL;
/**
* <p>Decomposition mode value. With NO_DECOMPOSITION set, Strings
* will not be decomposed for collation. This is the default
* decomposition setting unless otherwise specified by the locale
* used to create the Collator.</p>
*
* <p><strong>Note</strong> this value is different from the JDK's.</p>
* @see #CANONICAL_DECOMPOSITION
* @see #getDecomposition
* @see #setDecomposition
* @stable ICU 2.4
*/
public final static int NO_DECOMPOSITION = CollationAttribute.VALUE_OFF;
/**
* <p>Decomposition mode value. With CANONICAL_DECOMPOSITION set,
* characters that are canonical variants according to the Unicode standard
* will be decomposed for collation.</p>
*
* <p>CANONICAL_DECOMPOSITION corresponds to Normalization Form D as
* described in <a href="http://www.unicode.org/unicode/reports/tr15/">
* Unicode Technical Report #15</a>.
* </p>
* @see #NO_DECOMPOSITION
* @see #getDecomposition
* @see #setDecomposition
* @stable ICU 2.4
*/
public final static int CANONICAL_DECOMPOSITION
= CollationAttribute.VALUE_ON;
// Collation result constants -----------------------------------
// corresponds to ICU's UCollationResult enum balues
/**
* string a == string b
* @stable ICU 2.4
*/
public static final int RESULT_EQUAL = 0;
/**
* string a > string b
* @stable ICU 2.4
*/
public static final int RESULT_GREATER = 1;
/**
* string a < string b
* @stable ICU 2.4
*/
public static final int RESULT_LESS = -1;
/**
* accepted by most attributes
* @stable ICU 2.4
*/
public static final int RESULT_DEFAULT = -1;
// public methods -----------------------------------------------
/**
* Factory method to create an appropriate Collator which uses the default
* locale collation rules.
* Current implementation createInstance() returns a RuleBasedCollator(Locale)
* instance. The RuleBasedCollator will be created in the following order,
* <ul>
* <li> Data from argument locale resource bundle if found, otherwise
* <li> Data from parent locale resource bundle of arguemtn locale if found,
* otherwise
* <li> Data from built-in default collation rules if found, other
* <li> null is returned
* </ul>
* @return an instance of Collator
* @stable ICU 2.4
*/
public static Collator getInstance()
{
return getInstance(null);
}
/**
* Factory method to create an appropriate Collator which uses the argument
* locale collation rules.<br>
* Current implementation createInstance() returns a RuleBasedCollator(Locale)
* instance. The RuleBasedCollator will be created in the following order,
* <ul>
* <li> Data from argument locale resource bundle if found, otherwise
* <li> Data from parent locale resource bundle of arguemtn locale if found,
* otherwise
* <li> Data from built-in default collation rules if found, other
* <li> null is returned
* </ul>
* @param locale to be used for collation
* @return an instance of Collator
* @stable ICU 2.4
*/
public static Collator getInstance(Locale locale)
{
RuleBasedCollator result = new RuleBasedCollator(locale);
return result;
}
/**
* Locale dependent equality check for the argument strings.
* @param source string
* @param target string
* @return true if source is equivalent to target, false otherwise
* @stable ICU 2.4
*/
public boolean equals(String source, String target)
{
return (compare(source, target) == RESULT_EQUAL);
}
/**
* Checks if argument object is equals to this object.
* @param target object
* @return true if source is equivalent to target, false otherwise
* @stable ICU 2.4
*/
public abstract boolean equals(Object target);
/**
* Makes a copy of the current object.
* @return a copy of this object
* @stable ICU 2.4
*/
public abstract Object clone() throws CloneNotSupportedException;
/**
* The comparison function compares the character data stored in two
* different strings. Returns information about whether a string is less
* than, greater than or equal to another string.
* <p>Example of use:
* <pre>
* . Collator myCollation = Collator.getInstance(Locale::US);
* . myCollation.setStrength(CollationAttribute.VALUE_PRIMARY);
* . // result would be CollationAttribute.VALUE_EQUAL
* . // ("abc" == "ABC")
* . // (no primary difference between "abc" and "ABC")
* . int result = myCollation.compare("abc", "ABC",3);
* . myCollation.setStrength(CollationAttribute.VALUE_TERTIARY);
* . // result would be Collation.LESS (abc" <<< "ABC")
* . // (with tertiary difference between "abc" and "ABC")
* . int result = myCollation.compare("abc", "ABC",3);
* </pre>
* @param source source string.
* @param target target string.
* @return result of the comparison, Collator.RESULT_EQUAL,
* Collator.RESULT_GREATER or Collator.RESULT_LESS
* @stable ICU 2.4
*/
public abstract int compare(String source, String target);
/**
* Get the decomposition mode of this Collator.
* @return the decomposition mode
* @see #CANONICAL_DECOMPOSITION
* @see #NO_DECOMPOSITION
* @stable ICU 2.4
*/
public abstract int getDecomposition();
/**
* Set the normalization mode used int this object
* The normalization mode influences how strings are compared.
* @param mode desired normalization mode
* @see #CANONICAL_DECOMPOSITION
* @see #NO_DECOMPOSITION
* @stable ICU 2.4
*/
public abstract void setDecomposition(int mode);
/**
* Determines the minimum strength that will be use in comparison or
* transformation.
* <p>
* E.g. with strength == SECONDARY, the tertiary difference is ignored
* </p>
* <p>
* E.g. with strength == PRIMARY, the secondary and tertiary difference
* are ignored.
* </p>
* @return the current comparison level.
* @see #PRIMARY
* @see #SECONDARY
* @see #TERTIARY
* @see #QUATERNARY
* @see #IDENTICAL
* @stable ICU 2.4
*/
public abstract int getStrength();
/**
* Gets the attribute to be used in comparison or transformation.
* @param type the attribute to be set from CollationAttribute
* @return value attribute value from CollationAttribute
* @stable ICU 2.4
*/
public abstract int getAttribute(int type);
/**
* Sets the minimum strength to be used in comparison or transformation.
* <p>Example of use:
* <pre>
* . Collator myCollation = Collator.createInstance(Locale::US);
* . myCollation.setStrength(PRIMARY);
* . // result will be "abc" == "ABC"
* . // tertiary differences will be ignored
* . int result = myCollation->compare("abc", "ABC");
* </pre>
* @param strength the new comparison level.
* @see #PRIMARY
* @see #SECONDARY
* @see #TERTIARY
* @see #QUATERNARY
* @see #IDENTICAL
* @stable ICU 2.4
*/
public abstract void setStrength(int strength);
/**
* Sets the attribute to be used in comparison or transformation.
* <p>Example of use:
* <pre>
* . Collator myCollation = Collator.createInstance(Locale::US);
* . myCollation.setAttribute(CollationAttribute.CASE_LEVEL,
* . CollationAttribute.VALUE_ON);
* . int result = myCollation->compare("\\u30C3\\u30CF",
* . "\\u30C4\\u30CF");
* . // result will be Collator.RESULT_LESS.
* </pre>
* @param type the attribute to be set from CollationAttribute
* @param value attribute value from CollationAttribute
* @stable ICU 2.4
*/
public abstract void setAttribute(int type, int value);
/**
* Get the sort key as an CollationKey object from the argument string.
* To retrieve sort key in terms of byte arrays, use the method as below<br>
* <code>
* Collator collator = Collator.getInstance();
* CollationKey collationkey = collator.getCollationKey("string");
* byte[] array = collationkey.toByteArray();
* </code><br>
* Byte array result are zero-terminated and can be compared using
* java.util.Arrays.equals();
* @param source string to be processed.
* @return the sort key
* @stable ICU 2.4
*/
public abstract CollationKey getCollationKey(String source);
/**
* Returns a hash of this collation object
* @return hash of this collation object
* @stable ICU 2.4
*/
public abstract int hashCode();
// BEGIN android-added
public static Locale[] getAvailableLocales() {
String[] locales = NativeCollation.getAvailableLocalesImpl();
Locale[] result = new Locale[locales.length];
String locale;
int index, index2;
for(int i = 0; i < locales.length; i++) {
locale = locales[i];
index = locale.indexOf('_');
index2 = locale.lastIndexOf('_');
if(index == -1) {
result[i] = new Locale(locales[i]);
} else if(index == 2 && index == index2) {
result[i] = new Locale(
locale.substring(0,2),
locale.substring(3,5));
} else if(index == 2 && index2 > index) {
result[i] = new Locale(
locale.substring(0,index),
locale.substring(index + 1,index2),
locale.substring(index2 + 1));
}
}
return result;
}
// END android-added
}
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