public final class SingleTokenTokenStream extends TokenStream
TokenStream
containing a single token.AttributeSource.AttributeFactory, AttributeSource.State
Constructor and Description |
---|
SingleTokenTokenStream(Token token) |
Modifier and Type | Method and Description |
---|---|
Token |
getToken() |
boolean |
incrementToken()
Consumers (i.e.,
IndexWriter ) use this method to advance the stream to
the next token. |
void |
reset()
Resets this stream to the beginning.
|
void |
setToken(Token token) |
close, end
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, restoreState, toString
public SingleTokenTokenStream(Token token)
public final boolean incrementToken() throws IOException
TokenStream
IndexWriter
) use this method to advance the stream to
the next token. Implementing classes must implement this method and update
the appropriate AttributeImpl
s with the attributes of the next
token.
The producer must make no assumptions about the attributes after the method
has been returned: the caller may arbitrarily change it. If the producer
needs to preserve the state for subsequent calls, it can use
AttributeSource.captureState()
to create a copy of the current attribute state.
This method is called for every token of a document, so an efficient
implementation is crucial for good performance. To avoid calls to
AttributeSource.addAttribute(Class)
and AttributeSource.getAttribute(Class)
,
references to all AttributeImpl
s that this stream uses should be
retrieved during instantiation.
To ensure that filters and consumers know which attributes are available,
the attributes must be added during instantiation. Filters and consumers
are not required to check for availability of attributes in
TokenStream.incrementToken()
.
incrementToken
in class TokenStream
IOException
public void reset() throws IOException
TokenStream
TokenStream.reset()
is not needed for
the standard indexing process. However, if the tokens of a
TokenStream
are intended to be consumed more than once, it is
necessary to implement TokenStream.reset()
. Note that if your TokenStream
caches tokens and feeds them back again after a reset, it is imperative
that you clone the tokens when you store them away (on the first pass) as
well as when you return them (on future passes after TokenStream.reset()
).reset
in class TokenStream
IOException
public Token getToken()
public void setToken(Token token)