Examples of Collator

• com.hazelcast.mapreduce.Collator
  This interface can be implemented to define a Collator which is executed after calculation of the MapReduce algorithm on remote cluster nodes but before returning the final result.
  Collator can for example be used to sum up a final value. @param < ValueIn> value type of the resulting values @param < ValueOut> type for the collated result @since 3.2
• com.ibm.icu.text.Collator
  nicode.org>Unicode Consortium's specifications for the Unicode Collation Algorithm (UCA), there are 5 different levels of strength used in comparisons:

  • 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.
  • 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.
  • 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.
  • QUATERNARY strength: When punctuation is ignored (see Ignoring Punctuations in the user guide) 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.
  • 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.

  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.

  For more information about the collation service see the users guide.

  Examples of use

   // 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"); } 

  @see CollationKey @author Syn Wee Quek @stable ICU 2.8
• java.text.Collator
  are 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 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, CollationKeys 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. See the class description for {@link CollationKey}for an example using CollationKeys. @see RuleBasedCollator @see CollationKey @see CollationElementIterator @see Locale @version 1.46, 07/23/06 @author Helena Shih, Laura Werner, Richard Gillam

Examples of java.text.Collator

Examples of java.text.Collator