Package net.sf.ehcache.search

Class NullResults

  • All Implemented Interfaces:
    Results
    public class NullResults
extends java.lang.Object
implements Results
    An empty result instance
    Author:
    teck

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static NullResults INSTANCE
      A global instance that can be freely shared with the world since this type has no state

    • Constructor Summary

      Constructors 
      Constructor Description
      NullResults()  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.util.List<Result> all()
      List containing all of the search results.
      void discard()
      Discard this query result.
      boolean hasAggregators()
      Whether the results contains aggregates
      boolean hasAttributes()
      Whether the Results have cache attributes included.
      boolean hasKeys()
      Whether the Results have cache keys included.
      boolean hasValues()
      Whether the Results have cache values included.
      java.util.List<Result> range​(int start, int count)
      Retrieve a subset of the cache results.
      int size()
      Results size

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • INSTANCE

        public static final NullResults INSTANCE
        A global instance that can be freely shared with the world since this type has no state

    • Constructor Detail

      • NullResults

        public NullResults()

    • Method Detail

      • discard

        public void discard()
        Discard this query result. This call is not mandatory but is recommended after the caller is done with results. It can allow the cache, which may be distributed, to immediately free any resources associated with this result.

        Multiple calls are ignored. Attempting to read results from this instance after this method has been called will produce SearchException

        Specified by:
        discard in interface Results

      • range

        public java.util.List<Result> range​(int start,
                                    int count)
                             throws SearchException,
                                    java.lang.IndexOutOfBoundsException
        Retrieve a subset of the cache results. This method is useful when showing "paged" results in a user interface.
        Specified by:
        range in interface Results
        Parameters:
        start - starting index to access
        count - the number of results to return
        Returns:
        a List of the given size. This list will be smaller than the requested size if no more results are available. If there are no more results an empty list will be returned.
        Throws:
        SearchException
        java.lang.IndexOutOfBoundsException

      • size

        public int size()
        Results size
        Specified by:
        size in interface Results
        Returns:
        number of results present

      • hasKeys

        public boolean hasKeys()
        Whether the Results have cache keys included. If so these can be extracted from the Result object.
        Specified by:
        hasKeys in interface Results
        Returns:
        true if keys are included

      • hasValues

        public boolean hasValues()
        Whether the Results have cache values included. If so these can be extracted from the Result object.
        Specified by:
        hasValues in interface Results
        Returns:
        true if values are included

      • hasAttributes

        public boolean hasAttributes()
        Whether the Results have cache attributes included. If so these can be extracted from the Result object.
        Specified by:
        hasAttributes in interface Results
        Returns:
        true if attributes are included

      • hasAggregators

        public boolean hasAggregators()
        Whether the results contains aggregates
        Specified by:
        hasAggregators in interface Results
        Returns:
        true if this is an aggregate