org.apache.lucene.analysis.payloads
Class TokenOffsetPayloadTokenFilter
java.lang.Object
org.apache.lucene.util.AttributeSource
org.apache.lucene.analysis.TokenStream
org.apache.lucene.analysis.TokenFilter
org.apache.lucene.analysis.payloads.TokenOffsetPayloadTokenFilter
public class TokenOffsetPayloadTokenFilter
- extends TokenFilter
Adds the Token.setStartOffset(int)
and Token.setEndOffset(int)
First 4 bytes are the start
Method Summary |
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. |
Methods inherited from class org.apache.lucene.util.AttributeSource |
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, restoreState, toString |
offsetAtt
protected OffsetAttribute offsetAtt
payAtt
protected PayloadAttribute payAtt
TokenOffsetPayloadTokenFilter
public TokenOffsetPayloadTokenFilter(TokenStream input)
incrementToken
public final boolean incrementToken()
throws IOException
- Description copied from class:
TokenStream
- Consumers (i.e.,
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()
.
- Overrides:
incrementToken
in class TokenStream
- Returns:
- false for end of stream; true otherwise
Note that this method will be defined abstract in Lucene
3.0.
- Throws:
IOException
next
public final Token next(Token reusableToken)
throws IOException
- Deprecated. Will be removed in Lucene 3.0. This method is final, as it should
not be overridden. Delegates to the backwards compatibility layer.
- Description copied from class:
TokenStream
- Returns the next token in the stream, or null at EOS. When possible, the
input Token should be used as the returned Token (this gives fastest
tokenization performance), but this is not required and a new Token may be
returned. Callers may re-use a single Token instance for successive calls
to this method.
This implicitly defines a "contract" between consumers (callers of this
method) and producers (implementations of this method that are the source
for tokens):
- A consumer must fully consume the previously returned
Token
before calling this method again.
- A producer must call
Token.clear()
before setting the fields in
it and returning it
Also, the producer must make no assumptions about a Token
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.
- Overrides:
next
in class TokenStream
- Parameters:
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.)
- Returns:
- next
Token
in the stream or null if end-of-stream was hit
- Throws:
IOException
next
public final Token next()
throws IOException
- Deprecated. Will be removed in Lucene 3.0. This method is final, as it should
not be overridden. Delegates to the backwards compatibility layer.
- Description copied from class:
TokenStream
- Returns the next
Token
in the stream, or null at EOS.
- Overrides:
next
in class TokenStream
- Throws:
IOException
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