Package com.tangosol.util.comparator

Interface QueryMapComparator<T>

All Superinterfaces:
Comparator<T>
All Known Implementing Classes:
AbstractCompositeExtractor, AbstractExtractor, ChainedComparator, ChainedExtractor, ChainedFragmentExtractor, ComparisonValueExtractor, ConditionalExtractor, DeserializationAccelerator, EntryComparator, EntryExtractor, ExtractorComparator, FragmentExtractor, IdentityExtractor, InverseComparator, KeyExtractor, MultiExtractor, PartitionedJCacheStatistics.CacheStatisticsExtractor, PofExtractor, ReflectionExtractor, SafeComparator, ScriptValueExtractor, UniversalExtractor
public interface QueryMapComparator<T> extends Comparator<T>
This interface is used by Comparator implementations that can use value extraction optimization exposed by the QueryMap.Entry interface.
Author:
cp/gg 2002.12.13, 2006.06.12

  • Method Details

    • compareEntries

      int compareEntries(QueryMap.Entry<?,T> entry1, QueryMap.Entry<?,T> entry2)
      Compare two entries based on the rules specified by Comparator.

      If possible, use the extract method to optimize the value extraction process.

      This method is expected to be implemented by Comparator wrappers, such as ChainedComparator and InverseComparator, which simply pass on this invocation to the wrapped Comparator objects if they too implement this interface, or to invoke their default compare method passing the actual objects (not the extracted values) obtained from the extractor using the passed entries.

      This interface is also expected to be implemented by ValueExtractor implementations that implement the Comparator interface. It is expected that in most cases, the Comparator wrappers will eventually terminate at (i.e. delegate to) ValueExtractors that also implement this interface.

      Parameters:
      entry1 - the first entry to compare values from; read-only
      entry2 - the second entry to compare values from; read-only
      Returns:
      a negative integer, zero, or a positive integer as the first entry denotes a value that is is less than, equal to, or greater than the value denoted by the second entry
      Throws:
      ClassCastException - if the arguments' types prevent them from being compared by this Comparator.
      WrapperException - if the extractor encounters an exception in the course of extracting the value
      IllegalArgumentException - if the extractor cannot handle the passed objects for any other reason; an implementor should include a descriptive message
      Since:
      Coherence 3.2