org.apache.lucene.analysis.payloads
Class DelimitedPayloadTokenFilter

java.lang.Object
  extended by org.apache.lucene.util.AttributeSource
      extended by org.apache.lucene.analysis.TokenStream
          extended by org.apache.lucene.analysis.TokenFilter
              extended by org.apache.lucene.analysis.payloads.DelimitedPayloadTokenFilter

public final class DelimitedPayloadTokenFilter
extends TokenFilter

Characters before the delimiter are the "token", those after are the payload.

For example, if the delimiter is '|', then for the string "foo|bar", foo is the token and "bar" is a payload.

Note, you can also include a PayloadEncoder to convert the payload in an appropriate way (from characters to bytes).

Note make sure your Tokenizer doesn't split on the delimiter, or this won't work

See Also:
PayloadEncoder

Nested Class Summary
 
Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource
AttributeSource.AttributeFactory, AttributeSource.State
 
Field Summary
static char DEFAULT_DELIMITER
           
protected  char delimiter
           
protected  PayloadEncoder encoder
           
protected  PayloadAttribute payAtt
           
protected  TermAttribute termAtt
           
 
Fields inherited from class org.apache.lucene.analysis.TokenFilter
input
 
Constructor Summary
protected DelimitedPayloadTokenFilter(TokenStream input)
          Construct a token stream filtering the given input.
  DelimitedPayloadTokenFilter(TokenStream input, char delimiter, PayloadEncoder encoder)
           
 
Method Summary
 boolean incrementToken()
          Consumers (i.e., IndexWriter) use this method to advance the stream to the next token.
 
Methods inherited from class org.apache.lucene.analysis.TokenFilter
close, end, reset
 
Methods inherited from class org.apache.lucene.analysis.TokenStream
getOnlyUseNewAPI, next, next, setOnlyUseNewAPI
 
Methods inherited from class org.apache.lucene.util.AttributeSource
addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, restoreState, toString
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Field Detail

DEFAULT_DELIMITER

public static final char DEFAULT_DELIMITER
See Also:
Constant Field Values

delimiter

protected char delimiter

termAtt

protected TermAttribute termAtt

payAtt

protected PayloadAttribute payAtt

encoder

protected PayloadEncoder encoder
Constructor Detail

DelimitedPayloadTokenFilter

protected DelimitedPayloadTokenFilter(TokenStream input)
Construct a token stream filtering the given input.


DelimitedPayloadTokenFilter

public DelimitedPayloadTokenFilter(TokenStream input,
                                   char delimiter,
                                   PayloadEncoder encoder)
Method Detail

incrementToken

public 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 AttributeImpls 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 AttributeImpls 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


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