| /* |
| ******************************************************************************* |
| * Copyright (C) 1996-2006, International Business Machines Corporation and * |
| * others. All Rights Reserved. * |
| ******************************************************************************* |
| */ |
| |
| package com.ibm.icu.text; |
| |
| import java.util.Comparator; |
| import java.util.Locale; |
| |
| import com.ibm.icu.util.ULocale; |
| |
| /** |
| * <p>Collator performs locale-sensitive string comparison.</p> |
| * |
| * <p>Following the <a href=http://www.unicode.org>Unicode |
| * Consortium</a>'s specifications for the |
| * <a href="http://www.unicode.org/unicode/reports/tr10/"> Unicode Collation |
| * Algorithm (UCA)</a>, there are 5 different levels of strength used |
| * in comparisons: |
| * |
| * <ul> |
| * <li>PRIMARY strength: Typically, this is used to denote differences between |
| * base characters (for example, "a" < "b"). |
| * It is the strongest difference. For example, dictionaries are divided |
| * into different sections by base character. |
| * <li>SECONDARY strength: Accents in the characters are considered secondary |
| * differences (for example, "as" < "às" < "at"). Other |
| * differences |
| * between letters can also be considered secondary differences, depending |
| * on the language. A secondary difference is ignored when there is a |
| * primary difference anywhere in the strings. |
| * <li>TERTIARY strength: Upper and lower case differences in characters are |
| * distinguished at tertiary strength (for example, "ao" < "Ao" < |
| * "aò"). In addition, a variant of a letter differs from the base |
| * form on the tertiary strength (such as "A" and "Ⓐ"). Another |
| * example is the |
| * difference between large and small Kana. A tertiary difference is ignored |
| * when there is a primary or secondary difference anywhere in the strings. |
| * <li>QUATERNARY strength: When punctuation is ignored |
| * <a href="http://icu.sourceforge.net/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 (for example, |
| * "ab" < "a-b" < "aB"). |
| * This difference is ignored when there is a PRIMARY, SECONDARY or TERTIARY |
| * difference. The QUATERNARY strength should only be used if ignoring |
| * punctuation is required. |
| * <li>IDENTICAL strength: |
| * 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. |
| * For example, Hebrew cantellation marks are only distinguished at this |
| * strength. This strength should be used sparingly, as only code point |
| * value differences between two strings is an extremely rare occurrence. |
| * Using this strength substantially decreases the performance for both |
| * comparison and collation key generation APIs. This strength also |
| * increases the size of the collation key. |
| * </ul> |
| * |
| * Unlike the JDK, ICU4J's Collator deals only with 2 decomposition modes, |
| * the canonical decomposition mode and one that does not use any decomposition. |
| * The compatibility decomposition mode, java.text.Collator.FULL_DECOMPOSITION |
| * is not supported here. If the canonical |
| * decomposition mode is set, the Collator handles un-normalized text properly, |
| * producing the same results as if the text were normalized in NFD. If |
| * canonical decomposition is turned off, it is the user's responsibility to |
| * ensure that all text is already in the appropriate form before performing |
| * a comparison or before getting a CollationKey.</p> |
| * |
| * <p>For more information about the collation service see the |
| * <a href="http://icu.sourceforge.net/userguide/Collate_Intro.html">users |
| * guide</a>.</p> |
| * |
| * <p>Examples of use |
| * <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"); |
| * } |
| * |
| * The following example shows how to compare two strings using the |
| * Collator for the default locale. |
| * |
| * // Compare two strings in the default locale |
| * Collator myCollator = Collator.getInstance(); |
| * myCollator.setDecomposition(NO_DECOMPOSITION); |
| * if (myCollator.compare("à\u0325", "a\u0325̀") != 0) { |
| * System.out.println("à\u0325 is not equals to a\u0325̀ without decomposition"); |
| * myCollator.setDecomposition(CANONICAL_DECOMPOSITION); |
| * if (myCollator.compare("à\u0325", "a\u0325̀") != 0) { |
| * System.out.println("Error: à\u0325 should be equals to a\u0325̀ with decomposition"); |
| * } |
| * else { |
| * System.out.println("à\u0325 is equals to a\u0325̀ with decomposition"); |
| * } |
| * } |
| * else { |
| * System.out.println("Error: à\u0325 should be not equals to a\u0325̀ without decomposition"); |
| * } |
| * </pre> |
| * </p> |
| * @see CollationKey |
| * @author Syn Wee Quek |
| * @stable ICU 2.8 |
| */ |
| public class Collator implements Comparator, Cloneable |
| { |
| /** |
| * @internal |
| */ |
| private final java.text.Collator collator; |
| |
| /** |
| * @internal |
| */ |
| private Collator(java.text.Collator delegate) { |
| this.collator = delegate; |
| } |
| |
| /** |
| * Create a collator with a null delegate. |
| * For use by possible subclassers. This is present since |
| * the original Collator is abstract, and so, in theory |
| * subclassable. All member APIs must be overridden. |
| */ |
| protected Collator() { |
| this.collator = null; |
| } |
| |
| // 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 2.8 |
| */ |
| public final static int PRIMARY = java.text.Collator.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 2.8 |
| */ |
| public final static int SECONDARY = java.text.Collator.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 2.8 |
| */ |
| public final static int TERTIARY = java.text.Collator.TERTIARY; |
| |
| /** |
| * Fourth level collator strength value. |
| * When punctuation is ignored |
| * <a href="http://icu.sourceforge.net/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 2.8 |
| */ |
| public final static int QUATERNARY = java.text.Collator.IDENTICAL; |
| |
| /** |
| * <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 2.8 |
| */ |
| public final static int IDENTICAL = java.text.Collator.FULL_DECOMPOSITION; |
| |
| /** |
| * This is for backwards compatibility with Java APIs only. It |
| * should not be used, IDENTICAL should be used instead. ICU's |
| * collation does not support Java's FULL_DECOMPOSITION mode. |
| * @draft ICU 3.4 |
| * @deprecated Backwards compatibility with Java only. |
| */ |
| public final static int FULL_DECOMPOSITION = java.text.Collator.FULL_DECOMPOSITION; |
| |
| /** |
| * <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 2.8 |
| */ |
| public final static int NO_DECOMPOSITION = java.text.Collator.NO_DECOMPOSITION; |
| |
| /** |
| * <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 2.8 |
| */ |
| public final static int CANONICAL_DECOMPOSITION = java.text.Collator.CANONICAL_DECOMPOSITION; |
| |
| // public methods -------------------------------------------------------- |
| |
| // public setters -------------------------------------------------------- |
| |
| /** |
| * <p>Sets this Collator's strength property. The strength property |
| * determines the minimum level of difference considered significant |
| * during comparison.</p> |
| * |
| * <p>The default strength for the Collator is TERTIARY, unless specified |
| * otherwise by the locale used to create the Collator.</p> |
| * |
| * <p>See the Collator class description for an example of use.</p> |
| * @param newStrength the new strength value. |
| * @see #getStrength |
| * @see #PRIMARY |
| * @see #SECONDARY |
| * @see #TERTIARY |
| * @see #QUATERNARY |
| * @see #IDENTICAL |
| * @exception IllegalArgumentException if the new strength value is not one |
| * of PRIMARY, SECONDARY, TERTIARY, QUATERNARY or IDENTICAL. |
| * @stable ICU 2.8 |
| */ |
| public void setStrength(int newStrength) { |
| collator.setStrength(newStrength); |
| } |
| |
| /** |
| * <p>Set the decomposition mode of this Collator. Setting this |
| * decomposition property with CANONICAL_DECOMPOSITION allows the |
| * Collator to handle un-normalized text properly, producing the |
| * same results as if the text were normalized. If |
| * NO_DECOMPOSITION is set, it is the user's responsibility to |
| * insure that all text is already in the appropriate form before |
| * a comparison or before getting a CollationKey. Adjusting |
| * decomposition mode allows the user to select between faster and |
| * more complete collation behavior.</p> |
| * |
| * <p>Since a great many of the world's languages do not require |
| * text normalization, most locales set NO_DECOMPOSITION as the |
| * default decomposition mode.</p> |
| * |
| * The default decompositon mode for the Collator is |
| * NO_DECOMPOSITON, unless specified otherwise by the locale used |
| * to create the Collator.</p> |
| * |
| * <p>See getDecomposition for a description of decomposition |
| * mode.</p> |
| * |
| * @param decomposition the new decomposition mode |
| * @see #getDecomposition |
| * @see #NO_DECOMPOSITION |
| * @see #CANONICAL_DECOMPOSITION |
| * @exception IllegalArgumentException If the given value is not a valid |
| * decomposition mode. |
| * @stable ICU 2.8 |
| */ |
| public void setDecomposition(int decomposition) { |
| collator.setDecomposition(decomposition); |
| } |
| |
| // public getters -------------------------------------------------------- |
| |
| /** |
| * Gets the Collator for the current default locale. |
| * The default locale is determined by java.util.Locale.getDefault(). |
| * @return the Collator for the default locale (for example, en_US) if it |
| * is created successfully. Otherwise if there is no Collator |
| * associated with the current locale, the default UCA collator |
| * will be returned. |
| * @see java.util.Locale#getDefault() |
| * @see #getInstance(Locale) |
| * @stable ICU 2.8 |
| */ |
| public static final Collator getInstance() { |
| return new Collator(java.text.Collator.getInstance()); |
| } |
| |
| /** |
| * Gets the Collator for the desired locale. |
| * @param locale the desired locale. |
| * @return Collator for the desired locale if it is created successfully. |
| * Otherwise if there is no Collator |
| * associated with the current locale, a default UCA collator will |
| * be returned. |
| * @see java.util.Locale |
| * @see java.util.ResourceBundle |
| * @see #getInstance(Locale) |
| * @see #getInstance() |
| * @stable ICU 3.4.3 |
| */ |
| public static final Collator getInstance(ULocale locale) { |
| return getInstance(locale.toLocale()); |
| } |
| |
| /** |
| * Gets the Collator for the desired locale. |
| * @param locale the desired locale. |
| * @return Collator for the desired locale if it is created successfully. |
| * Otherwise if there is no Collator |
| * associated with the current locale, a default UCA collator will |
| * be returned. |
| * @see java.util.Locale |
| * @see java.util.ResourceBundle |
| * @see #getInstance(ULocale) |
| * @see #getInstance() |
| * @stable ICU 2.8 |
| */ |
| public static final Collator getInstance(Locale locale) { |
| return new Collator(java.text.Collator.getInstance(locale)); |
| } |
| |
| /** |
| * Get the set of locales, as Locale objects, for which collators |
| * are installed. Note that Locale objects do not support RFC 3066. |
| * @return the list of locales in which collators are installed. |
| * This list includes any that have been registered, in addition to |
| * those that are installed with ICU4J. |
| * @stable ICU 2.4 |
| */ |
| public static Locale[] getAvailableLocales() { |
| return java.text.Collator.getAvailableLocales(); |
| } |
| |
| /** |
| * Get the set of locales, as ULocale objects, for which collators |
| * are installed. ULocale objects support RFC 3066. |
| * @return the list of locales in which collators are installed. |
| * This list includes any that have been registered, in addition to |
| * those that are installed with ICU4J. |
| * @stable ICU 3.4.3 |
| */ |
| public static final ULocale[] getAvailableULocales() { |
| Locale[] locales = java.text.Collator.getAvailableLocales(); |
| ULocale[] ulocales = new ULocale[locales.length]; |
| for (int i = 0; i < locales.length; ++i) { |
| ulocales[i] = ULocale.forLocale(locales[i]); |
| } |
| return ulocales; |
| } |
| |
| /** |
| * Return an array of all possible keywords that are relevant to |
| * collation. At this point, the only recognized keyword for this |
| * service is "collation". |
| * @return an array of valid collation keywords. |
| * @see #getKeywordValues |
| * @draft ICU 3.0 |
| * @provisional |
| */ |
| public static final String[] getKeywords() { |
| return new String[0]; |
| } |
| |
| /** |
| * Given a keyword, return an array of all values for |
| * that keyword that are currently in use. |
| * @param keyword one of the keywords returned by getKeywords. |
| * @see #getKeywords |
| * @draft ICU 3.0 |
| * @provisional |
| */ |
| public static final String[] getKeywordValues(String keyword) { |
| return new String[0]; |
| } |
| |
| /** |
| * <p>Returns this Collator's strength property. The strength property |
| * determines the minimum level of difference considered significant. |
| * </p> |
| * <p> |
| * See the Collator class description for more details. |
| * </p> |
| * @return this Collator's current strength property. |
| * @see #setStrength |
| * @see #PRIMARY |
| * @see #SECONDARY |
| * @see #TERTIARY |
| * @see #QUATERNARY |
| * @see #IDENTICAL |
| * @stable ICU 2.8 |
| */ |
| public int getStrength() { |
| return collator.getStrength(); |
| } |
| |
| /** |
| * <p> |
| * Get the decomposition mode of this Collator. Decomposition mode |
| * determines how Unicode composed characters are handled. |
| * </p> |
| * <p> |
| * See the Collator class description for more details. |
| * </p> |
| * @return the decomposition mode |
| * @see #setDecomposition |
| * @see #NO_DECOMPOSITION |
| * @see #CANONICAL_DECOMPOSITION |
| * @stable ICU 2.8 |
| */ |
| public int getDecomposition() { |
| return collator.getDecomposition(); |
| } |
| |
| /** |
| * <p> |
| * Compares the source text String to the target text String according to |
| * this Collator's rules, strength and decomposition mode. |
| * Returns an integer less than, |
| * equal to or greater than zero depending on whether the source String is |
| * less than, equal to or greater than the target String. See the Collator |
| * class description for an example of use. |
| * </p> |
| * @param source the source String. |
| * @param target the target String. |
| * @return Returns an integer value. Value is less than zero if source is |
| * less than target, value is zero if source and target are equal, |
| * value is greater than zero if source is greater than target. |
| * @see CollationKey |
| * @see #getCollationKey |
| * @exception NullPointerException thrown if either arguments is null. |
| * IllegalArgumentException thrown if either source or target is |
| * not of the class String. |
| * @stable ICU 2.8 |
| */ |
| public int compare(Object source, Object target) { |
| return collator.compare(source, target); |
| } |
| |
| // public other methods ------------------------------------------------- |
| |
| /** |
| * Convenience method for comparing the equality of two text Strings using |
| * this Collator's rules, strength and decomposition mode. |
| * @param source the source string to be compared. |
| * @param target the target string to be compared. |
| * @return true if the strings are equal according to the collation |
| * rules, otherwise false. |
| * @see #compare |
| * @exception NullPointerException thrown if either arguments is null. |
| * @stable ICU 2.8 |
| */ |
| public boolean equals(String source, String target) { |
| return (compare(source, target) == 0); |
| } |
| |
| /** |
| * <p> |
| * Compares the source text String to the target text String according to |
| * this Collator's rules, strength and decomposition mode. |
| * Returns an integer less than, |
| * equal to or greater than zero depending on whether the source String is |
| * less than, equal to or greater than the target String. See the Collator |
| * class description for an example of use. |
| * </p> |
| * @param source the source String. |
| * @param target the target String. |
| * @return Returns an integer value. Value is less than zero if source is |
| * less than target, value is zero if source and target are equal, |
| * value is greater than zero if source is greater than target. |
| * @see CollationKey |
| * @see #getCollationKey |
| * @exception NullPointerException thrown if either arguments is null. |
| * @stable ICU 2.8 |
| */ |
| public int compare(String source, String target) { |
| return collator.compare(source, target); |
| } |
| |
| /** |
| * <p> |
| * Transforms the String into a CollationKey suitable for efficient |
| * repeated comparison. The resulting key depends on the collator's |
| * rules, strength and decomposition mode. |
| * </p> |
| * <p>See the CollationKey class documentation for more information.</p> |
| * @param source the string to be transformed into a CollationKey. |
| * @return the CollationKey for the given String based on this Collator's |
| * collation rules. If the source String is null, a null |
| * CollationKey is returned. |
| * @see CollationKey |
| * @see #compare(String, String) |
| * @stable ICU 2.8 |
| */ |
| public CollationKey getCollationKey(String source) { |
| return new CollationKey(collator.getCollationKey(source)); |
| } |
| |
| /** |
| * Return a string suitable for debugging. |
| * @return a string suitable for debugging |
| * @stable ICU 3.4.3 |
| */ |
| public String toString() { |
| return collator.toString(); |
| } |
| |
| /** |
| * Clone the collator. |
| * @return a clone of this collator. |
| * @stable ICU 2.6 |
| */ |
| public Object clone() throws CloneNotSupportedException { |
| return new Collator((java.text.Collator)collator.clone()); |
| } |
| |
| /** |
| * Return true if rhs is a Collator and compares the same as this. |
| * @return true if rhs equals this |
| * @stable ICU 3.4.3 |
| */ |
| public boolean equals(Object rhs) { |
| try { |
| return collator.equals(((Collator)rhs).collator); |
| } |
| catch (Exception e) { |
| return false; |
| } |
| } |
| |
| /** |
| * Return a hashCode. |
| * @return a hashCode |
| * @stable ICU 3.4.3 |
| */ |
| public int hashCode() { |
| return collator.hashCode(); |
| } |
| } |
