public 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. |
Token |
next()
Deprecated.
Will be removed in Lucene 3.0. This method is final, as it should
not be overridden. Delegates to the backwards compatibility layer.
|
Token |
next(Token reusableToken)
Deprecated.
Will be removed in Lucene 3.0. This method is final, as it should
not be overridden. Delegates to the backwards compatibility layer.
|
void |
reset()
Resets this stream to the beginning.
|
void |
setToken(Token token) |
close, end, getOnlyUseNewAPI, setOnlyUseNewAPI
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, restoreState, toString
public SingleTokenTokenStream(Token token)
public final boolean incrementToken() throws java.io.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)
or downcasts,
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
Note that this method will be defined abstract in Lucene 3.0.
java.io.IOException
public final Token next(Token reusableToken) throws java.io.IOException
TokenStream
This implicitly defines a "contract" between consumers (callers of this method) and producers (implementations of this method that are the source for tokens):
Token
before calling this method again.Token.clear()
before setting the fields in
it and returning itToken
after it
has been returned: the caller may arbitrarily change it. If the producer
needs to hold onto the Token
for subsequent calls, it must clone()
it before storing it. Note that a TokenFilter
is considered a
consumer.next
in class TokenStream
reusableToken
- a Token
that may or may not be used to return;
this parameter should never be null (the callee is not required to
check for null before using it, but it is a good idea to assert that
it is not null.)Token
in the stream or null if end-of-stream was hitjava.io.IOException
public final Token next() throws java.io.IOException
TokenStream
Token
in the stream, or null at EOS.next
in class TokenStream
java.io.IOException
public void reset() throws java.io.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
java.io.IOException
public Token getToken()
public void setToken(Token token)
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