CollationKey objects compare strings more quickly than is possible with Collation.compare( ). Objects of this class are returned by Collation.getCollationKey( ). To compare two CollationKey objects, invoke the compareTo( ) method of key A, passing the key B as an argument (both CollationKey objects must be created through the same Collation object). The return value of this method is less than zero if the key A is collated before the key B, equal to zero if they are equivalent for the purposes of collation, or greater than zero if the key A is collated after the key B. Use getSourceString( ) to obtain the string represented by a CollationKey.

Figure 15-5. java.text.CollationKey

public final class CollationKey implements Comparable<CollationKey> {
// No Constructor
// Public Instance Methods
     public int compareTo(CollationKey target);    Implements:Comparable
     public String getSourceString( );  
     public byte[ ] toByteArray( );  
// Methods Implementing Comparable
     public int compareTo(CollationKey target);  
// Public Methods Overriding Object
     public boolean equals(Object target);  
     public int hashCode( );  
}

Returned By

Collator.getCollationKey( ), RuleBasedCollator.getCollationKey( )