MultiReader

Construct a MultiReader aggregating the named set of (sub)readers. Directory locking for delete, undeleteAll, and setNorm operations is left to the subreaders.

Note that all subreaders are closed if this Multireader is closed.

Construct a MultiReader aggregating the named set of (sub)readers. Directory locking for delete, undeleteAll, and setNorm operations is left to the subreaders.

Clones the subreaders. (see clone()).

If subreaders are shared, then the reference count of those readers is increased to ensure that the subreaders remain open until the last referring reader is closed.

Returns the number of documents containing the term t.

Get the Document at the n ^th position. The FieldSelector may be used to determine what Fields to load and how they should be loaded. NOTE: If this Reader (more specifically, the underlying FieldsReader) is closed before the lazy Field is loaded an exception may be thrown. If you want the value of a lazy Field to be available after closing you must explicitly load it or fetch the Document again with a new loader.

NOTE: for performance reasons, this method does not check if the requested document is deleted, and therefore asking for a deleted document may yield unspecified results. Usually this is not required, however you can call isDeleted(int) with the requested document ID to verify the document is not deleted.

Get a list of unique field names that exist in this index and have the specified field option information.

Expert: returns the sequential sub readers that this reader is logically composed of. For example, IndexSearcher uses this API to drive searching by one sub reader at a time. If this reader is not composed of sequential child readers, it should return null. If this method returns an empty array, that means this reader is a null reader (for example a MultiReader that has no sub readers).

NOTE: You should not try using sub-readers returned by this method to make any changes (setNorm, deleteDocument, etc.). While this might succeed for one composite reader (like MultiReader), it will most likely lead to index corruption for other readers (like DirectoryReader obtained through open(IndexCommit, boolean). Use the parent reader directly.

Load the Term Vector into a user-defined data structure instead of relying on the parallel arrays of the TermFreqVector.

Map all the term vectors for all fields in a Document

Return a term frequency vector for the specified document and field. The returned vector contains terms and frequencies for the terms in the specified field of this document, if the field had the storeTermVector flag set. If termvectors had been stored with positions or offsets, a TermPositionVector is returned.

Return an array of term frequency vectors for the specified document. The array contains a vector for each vectorized field in the document. Each vector contains terms and frequencies for all terms in a given vectorized field. If no such fields existed, the method returns null. The term vectors that are returned may either be of type TermFreqVector or of type TermPositionVector if positions or offsets have been stored.

Not implemented.

Returns true if any documents have been deleted

Returns true if there are norms stored for this field.

Checks recursively if all subreaders are up to date.

Returns true if document n has been deleted

Checks is the index is optimized (if it has a single segment and no deletions). Not implemented in the IndexReader base class.

Returns one greater than the largest possible document number. This may be used to, e.g., determine how big to allocate an array which will have an element for every document number in an index.

Returns the byte-encoded normalization factor for the named field of every document. This is used by the search code to score documents.

Reads the byte-encoded normalization factor for the named field of every document. This is used by the search code to score documents.

Returns the number of documents in this index.

Tries to reopen the subreaders.
If one or more subreaders could be re-opened (i. e. subReader.reopen() returned a new instance != subReader), then a new MultiReader instance is returned, otherwise this instance is returned.

A re-opened instance might share one or more subreaders with the old instance. Index modification operations result in undefined behavior when performed before the old instance is closed. (see reopen()).

If subreaders are shared, then the reference count of those readers is increased to ensure that the subreaders remain open until the last referring reader is closed.

Returns an unpositioned TermDocs enumerator.

Returns an unpositioned TermPositions enumerator.

Returns an enumeration of all terms starting at a given term. If the given term does not exist, the enumeration is positioned at the first term greater than the supplied term. The enumeration is ordered by Term.compareTo(). Each term is greater than all that precede it in the enumeration.

Returns an enumeration of all the terms in the index. The enumeration is ordered by Term.compareTo(). Each term is greater than all that precede it in the enumeration. Note that after calling terms(), next() must be called on the resulting enumeration before calling other methods such as term().

Implements close.

Implements commit.

Implements deletion of the document numbered docNum. Applications should call deleteDocument(int) or deleteDocuments(Term).

If clone is true then we clone each of the subreaders

Implements setNorm in subclass.

Implements actual undeleteAll() in subclass.