public abstract class CompositeReader extends IndexReader
AtomicReaderContextfor all sub-readers via
IndexReader.leaves(). Alternatively, you can mimic an
AtomicReader(with a serious slowdown), by wrapping composite readers with
IndexReader instances for indexes on disk are usually constructed
with a call to one of the static
CompositeReader interface, it is not possible to directly get postings.
Concrete subclasses of IndexReader are usually constructed with a call to
one of the static
open() methods, e.g.
For efficiency, in this API documents are often referred to via document numbers, non-negative integers which each name a unique document in the index. These document numbers are ephemeral -- they may change as documents are added to and deleted from an index. Clients should thus not rely on a given document having the same number between sessions.
IndexReader instances are completely thread
safe, meaning multiple threads can call any of its methods,
concurrently. If your application requires external
synchronization, you should not synchronize on the
IndexReader instance; use your own
(non-Lucene) objects instead.
|Modifier||Constructor and Description|
|Modifier and Type||Method and Description|
Expert: returns the sequential sub readers that this reader is logically composed of.
addReaderClosedListener, close, decRef, docFreq, doClose, document, document, document, ensureOpen, equals, getCombinedCoreAndDeletesKey, getCoreCacheKey, getRefCount, getTermVector, getTermVectors, hasDeletions, hashCode, incRef, leaves, maxDoc, numDeletedDocs, numDocs, open, open, open, open, open, registerParentReader, removeReaderClosedListener, totalTermFreq, tryIncRef
protected abstract List<? extends IndexReader> getSequentialSubReaders()
public final CompositeReaderContext getContext()
IndexReader's sub-reader tree.
Iff this reader is composed of sub
readers, i.e. this reader being a composite reader, this method returns a
CompositeReaderContext holding the reader's direct children as well as a
view of the reader tree's atomic leaf contexts. All sub-
IndexReaderContext instances referenced from this readers top-level
context are private to this reader and are not shared with another context
tree. For example, IndexSearcher uses this API to drive searching by one
atomic leaf reader at a time. If this reader is not composed of child
readers, this method returns an
Note: Any of the sub-
CompositeReaderContext instances referenced
from this top-level context do not support
Only the top-level context maintains the convenience leaf-view
for performance reasons.
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