org.apache.solr.analysis

Class BufferedTokenStream

java.lang.Object

org.apache.lucene.util.AttributeSource

org.apache.lucene.analysis.TokenStream

org.apache.lucene.analysis.TokenFilter

org.apache.solr.analysis.BufferedTokenStream

All Implemented Interfaces:

Closeable

Deprecated.

This class does not support custom attributes. Extend TokenFilter instead, using AttributeSource.captureState() and AttributeSource.restoreState(State) which support all attributes.

@Deprecated
public abstract class BufferedTokenStream
extends TokenFilter

Handles input and output buffering of TokenStream

 // Example of a class implementing the rule "A" "B" => "Q" "B"
 class MyTokenStream extends BufferedTokenStream {
   public MyTokenStream(TokenStream input) {super(input);}
   protected Token process(Token t) throws IOException {
     if ("A".equals(t.termText())) {
       Token t2 = read();
       if (t2!=null && "B".equals(t2.termText())) t.setTermText("Q");
       if (t2!=null) pushBack(t2);
     }
     return t;
   }
 }

 // Example of a class implementing "A" "B" => "A" "A" "B"
 class MyTokenStream extends BufferedTokenStream {
   public MyTokenStream(TokenStream input) {super(input);}
   protected Token process(Token t) throws IOException {
     if ("A".equals(t.termText()) && "B".equals(peek(1).termText()))
       write((Token)t.clone());
     return t;
   }
 }
 

NOTE: BufferedTokenStream does not clone() any Tokens. This is instead the responsibility of the implementing subclass. In the "A" "B" => "A" "A" "B" example above, the subclass must clone the additional "A" it creates.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource

AttributeSource.AttributeFactory, AttributeSource.State

Field Summary

Fields inherited from class org.apache.lucene.analysis.TokenFilter

input

Constructor Summary

Constructors

Constructor and Description
BufferedTokenStream(TokenStream input) Deprecated.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	incrementToken() Deprecated.
protected Iterable<Token>	output() Deprecated. Provides direct Iterator access to the buffered output stream.
protected Token	peek(int n) Deprecated. Peek n tokens ahead in the buffered input stream, without modifying the stream.
protected abstract Token	process(Token t) Deprecated. Process a token.
protected void	pushBack(Token t) Deprecated. Push a token back into the buffered input stream, such that it will be returned by a future call to read()
protected Token	read() Deprecated. Read a token from the buffered input stream.
void	reset() Deprecated.
protected void	write(Token t) Deprecated. Write a token to the buffered output stream

Methods inherited from class org.apache.lucene.analysis.TokenFilter

close, end

Methods inherited from class org.apache.lucene.util.AttributeSource

addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, restoreState, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

BufferedTokenStream

public BufferedTokenStream(TokenStream input)

Deprecated.

Method Detail

process

protected abstract Token process(Token t)
                          throws IOException

Deprecated.

Process a token. Subclasses may read more tokens from the input stream, write more tokens to the output stream, or simply return the next token to be output. Subclasses may return null if the token is to be dropped. If a subclass writes tokens to the output stream and returns a non-null Token, the returned Token is considered to be at the head of the token output stream.

Throws:

IOException

incrementToken

public final boolean incrementToken()
                             throws IOException

Deprecated.

Specified by:

incrementToken in class TokenStream

Throws:

IOException

read

protected Token read()
              throws IOException

Deprecated.

Read a token from the buffered input stream.

Returns:

null at EOS

Throws:

IOException

pushBack

protected void pushBack(Token t)

Deprecated.

Push a token back into the buffered input stream, such that it will be returned by a future call to read()

peek

protected Token peek(int n)
              throws IOException

Deprecated.

Peek n tokens ahead in the buffered input stream, without modifying the stream.

Parameters:

n - Number of tokens into the input stream to peek, 1 based ... 0 is invalid

Returns:

a Token which exists in the input stream, any modifications made to this Token will be "real" if/when the Token is read() from the stream.

Throws:

IOException

write

protected void write(Token t)

Deprecated.

Write a token to the buffered output stream

output

protected Iterable<Token> output()

Deprecated.

Provides direct Iterator access to the buffered output stream. Modifying any token in this Iterator will affect the resulting stream.

reset

public void reset()
           throws IOException

Deprecated.

Overrides:

reset in class TokenFilter

Throws:

IOException