Package org.apache.lucene.index

Class IndexReaderContext

java.lang.Object
org.apache.lucene.index.IndexReaderContext
Direct Known Subclasses:
CompositeReaderContext, LeafReaderContext
public abstract class IndexReaderContext extends Object
A struct like class that represents a hierarchical relationship between IndexReader instances.

  • Field Details

    • parent

      public final CompositeReaderContext parent
      The reader context for this reader's immediate parent, or null if none

    • isTopLevel

      public final boolean isTopLevel
      true if this context struct represents the top level reader within the hierarchical context

    • docBaseInParent

      public final int docBaseInParent
      the doc base for this reader in the parent, 0 if parent is null

    • ordInParent

      public final int ordInParent
      the ord for this reader in the parent, 0 if parent is null

  • Method Details

    • id

      public Object id()
      Expert: Return an Object that uniquely identifies this context. The returned object does neither reference this IndexReaderContext nor the wrapped IndexReader.
      WARNING: This API is experimental and might change in incompatible ways in the next release.

    • reader

      public abstract IndexReader reader()
      Returns the IndexReader, this context represents.

    • leaves

      public abstract List<LeafReaderContext> leaves() throws UnsupportedOperationException
      Returns the context's leaves if this context is a top-level context. For convenience, if this is an LeafReaderContext this returns itself as the only leaf, and it will never return a null value.

      Note: this is convenience method since leaves can always be obtained by walking the context tree using children().

      Throws:
      UnsupportedOperationException - if this is not a top-level context.
      See Also:

    • children

      public abstract List<IndexReaderContext> children()
      Returns the context's children iff this context is a composite context otherwise null .