LuceneQuery (Apache Geode 1.9.2)
Date: 2019-10-15

org.apache.geode.cache.lucene

## Interface LuceneQuery<K,V>

-     public interface LuceneQuery<K,V>

  A query on a Lucene index. Instances of this interface are created using `LuceneQueryFactory.create(java.lang.String, java.lang.String, java.lang.String, java.lang.String)`. Once this query is constructed, use one of the find methods to find region entries that match this query.

  Instances obtained from `LuceneQueryFactory` are immutable, so they are safe for reuse and can be shared by multiple threads.

  Because Lucene indexes are maintained asynchronously, results returned from the find methods may not reflect the most recent updates to the region.

  Results are returned in order of their score with respect to this query.

- - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method and Description
    --- | ---
    `Collection<K>` | `findKeys()` Execute the query and return the region keys that match this query, up to the limit specified by `getLimit()`.
    `PageableLuceneQueryResults<K,V>` | `findPages()` Execute the query and get a `PageableLuceneQueryResults`.
    `List<LuceneResultStruct<K,V>>` | `findResults()` Execute the query and return a list of `LuceneResultStruct`s that match this query, up to the limit specified by `getLimit()` A `LuceneResultStruct` contains the region key, value, and a score for that entry.
    `Collection<V>` | `findValues()` Execute the query and return the region values that match this query, up to the limit specified by `getLimit()`
    `int` | `getLimit()` Get limit size setting of current query.
    `int` | `getPageSize()` Gets the page size setting of current query.

- - ### Method Detail

    - #### findKeys

          Collection<K> findKeys()
                          throws LuceneQueryException

      Execute the query and return the region keys that match this query, up to the limit specified by `getLimit()`.
      Returns:
        Collection of Apache Geode region keys that satisfy the Lucene query.
      Throws:
        `LuceneQueryException` - if the query could not be parsed or executed.
        `CacheClosedException` - if the cache was closed while the Lucene query was being executed.
        `FunctionException` - if the function execution mechanism encounters an error while executing the Lucene query.
        `PartitionOfflineException` - if the node containing the buckets required to execute the Lucene query goes offline.
        `CancelException` - if a cancel is in progress while the Lucene query was being executed.

    - #### findValues

          Collection<V> findValues()
                            throws LuceneQueryException

      Execute the query and return the region values that match this query, up to the limit specified by `getLimit()`
      Returns:
        a Collection of Apache Geode region values that satisfy the Lucene query.
      Throws:
        `LuceneQueryException` - if the query could not be parsed or executed.
        `CacheClosedException` - if the cache was closed while the Lucene query was being executed.
        `FunctionException` - if the function execution mechanism encounters an error while executing the Lucene query.
        `PartitionOfflineException` - if the node containing the buckets required to execute the Lucene query goes offline.
        `CancelException` - if a cancel is in progress while the Lucene query was being executed.

    - #### findResults

          List<LuceneResultStruct<K,V>> findResults()
                                             throws LuceneQueryException

      Execute the query and return a list of `LuceneResultStruct`s that match this query, up to the limit specified by `getLimit()` A `LuceneResultStruct` contains the region key, value, and a score for that entry.
      Returns:
        a List of LuceneResultStruct that match the Lucene query
      Throws:
        `LuceneQueryException` - if the query could not be parsed or executed.
        `CacheClosedException` - if the cache was closed while the Lucene query was being executed.
        `FunctionException` - if the function execution mechanism encounters an error while executing the Lucene query.
        `PartitionOfflineException` - if the node containing the buckets required to execute the Lucene query goes offline.
        `CancelException` - if a cancel is in progress while the Lucene query was being executed.

    - #### findPages

          PageableLuceneQueryResults<K,V> findPages()
                                             throws LuceneQueryException

      Execute the query and get a `PageableLuceneQueryResults`. The `PageableLuceneQueryResults` provides the ability to fetch a page of results at a time, as specified by `getPageSize()`
      Returns:
        a PageableLuceneQuery that can be used to fetch one page of result at a time.
      Throws:
        `LuceneQueryException` - if the query could not be parsed or executed.
        `CacheClosedException` - if the cache was closed while the Lucene query was being executed.
        `FunctionException` - if the function execution mechanism encounters an error while executing the Lucene query.
        `PartitionOfflineException` - if the node containing the buckets required to execute the Lucene query goes offline.
        `CancelException` - if a cancel is in progress while the Lucene query was being executed.

    - #### getPageSize

          int getPageSize()

      Gets the page size setting of current query. This page size is set while creating `LuceneQueryImpl` object
      Returns:
        int value representing the page size of the current query

    - #### getLimit

          int getLimit()

      Get limit size setting of current query. This value is the maximum number of results that can be returned by the Lucene query. This value is set while creating the `LuceneQueryImpl` object
      Returns:
        int value representing the limit of the current query